Polymeric light emitting substance and polymer light emitting device using the same

ABSTRACT

A polymeric light emitting substance having a polystyrene reduced number-average molecular weight of from 10 3  to 10 8 wherein this light emitting substance has in the main chain or side chain a metal complex structure showing light emission from the triplet excited state, and said substance can form a light emitting layer by industrially simple application methods such as a spin coat method, inkjet method, printing method and the like.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a polymeric light emitting substance, amethod of producing the same, a complex which can be a monomer used inproducing the same, and a polymer light emitting device using thispolymeric light emitting substance (hereinafter, referred to as polymerLED in some cases).

2. Description of the Related Art

Regarding light emitting materials used in a light emitting layer in alight emitting device, it is known that a device using in a lightemitting layer a metal complex showing light emission from the tripletexcited state (hereinafter, referred to as complex emitting tripletluminescence) has high light emitting efficiency.

As the complex emitting triplet luminescence, known are, for example,Ir(ppy) 3 containing iridium as a center metal (Appl. Phys. Lett., 75, 4(1999)), PtOEP containing platinum as a center metal (Nature, 395, 151(1998), Eu(TTA)3 phen containing europium as a center metal (Jpn. J.Appl. Phys., 34, 1883 (1995)) and the like.

However, for forming a light emitting layer using the above-mentionedknown complex emitting triplet luminescence, there are usually only usedmethods such as a vacuum deposition method and the like, and it isdifficult to form a light emitting layer by an application method.

An object of the present invention is to provide a novel light emittingsubstance having a complex emitting triplet luminescence structure inthe molecule and capable of forming a light emitting layer by anapplication method, a method of producing the same, a novel complexwhich can be a monomer used in producing the same, and a polymer lightemitting device using this polymeric light emitting substance.

SUMMARY OF THE INVENTION

The present inventors have intensively studied for solving theabove-mentioned problems, and resultantly found that a polymeric lightemitting substance having a polystyrene reduced number-average molecularweight of from 10³ to 10⁸ wherein this light emitting substance has inthe main chain or side chain a metal complex structure showing lightemission from the triplet excited state has a complex emitting tripletluminescence structure in the molecule, and a light emitting layer canbe formed by an application method using this light emitting substance,leading to completion of the invention.

DETAILED DESCRIPTION OF THE INVENTION

The polymeric light emitting substance is a polymeric light emittingsubstance having a polystyrene reduced number-average molecular weightof from 10³ to 10⁸ wherein this light emitting substance has in the mainchain or side chain a metal complex structure showing light emissionfrom the triplet excited state, and particularly, it is preferable thatthe polymeric light emitting substance is a conjugated type polymericlight emitting substance.

Here, the conjugated type polymeric light emitting substance means apolymeric light emitting substance in which a de-localized π electronpair is present along the main chain skeleton of a polymer. Regardingthis de-localized electron, an unpaired electron or lone electron pairmay participate in resonance instead of a double bond, in some cases.

A complex emitting triplet luminescence which is a mother body of ametal complex structure showing light emission from the triplet excitedstate, in the present invention, will be described.

The complex emitting triplet luminescence is usually a heavy metalcomplex, and refers, for example, to a complex which can causephosphorescence light emission from the above-mentioned complex.However, complexes providing observation of fluorescence light emissionin addition to this phosphorescence light emission are also included.

The center metal of a complex emitting triplet luminescence is usuallyan atom having an atomic number of 50 or more, and is a metalmanifesting a spin-orbital mutual action on this complex and showing apossibility of the intersystem crossing between the singlet state andthe triplet state.

As the center metal of a complex emitting triplet luminescence, forexample, rhenium, iridium, osmium, scandium, yttrium, platinum, gold,and europium such as lanthanoids, terbium, thulium, dysprosium,samarium, praseodymium, and the like, are listed, and iridium, platinum,gold and europium are preferable, iridium, platinum and gold areparticularly preferable.

The ligand of a complex emitting triplet luminescence is usually anorganic ligand, and the number of carbon atoms is usually from about 4to 60.

As the ligand of a complex emitting triplet luminescence, for example,8-quinolinol and derivatives thereof, benzoquinolinol and derivativesthereof, 2-phenyl-pyridine and derivatives thereof,2-phenyl-benzothiazole and derivatives thereof, 2-phenyl-benzoxazole andderivatives thereof, porphyrin and derivatives thereof, and the like arelisted.

Examples of the complex emitting triplet luminescence includefollowings.

Here, R represents each independently a group selected from a hydrogenatom, alkyl group, alkoxy group, alkylthio group, alkylsilyl group,alkylamino group, aryl group, aryloxy group, arylalkyl group, arylalkoxygroup, arylalkenyl group, aryl alkynyl group, arylamino group,monovalent heterocyclic compound group, and cyanno group. In order toimprove the solubility in a solvent, it is preferable that the repeatingunit including substituent has a form of little symmetry.

The alkyl group may be linear, branching or cyclic, and has usuallyabout one to 20 carbon atoms. Examples thereof include specificallymethyl group, ethyl group, propyl group, i-propyl group, butyl group,i-butyl group, t-butyl group, pentyl group, hexyl group, heptyl group,octyl group, 2-ethylhexyl group, nonyl group, decyl group,3,7-dimethyloctyl group, lauryl group, etc. Among them, pentyl group,hexyl group, octyl group, 2-ethylhexyl group, decyl group, and3,7-dimethyl octyl group are preferable.

The alkoxy group may be linear, branching or cyclic, and has usuallyabout one to 20 carbon atoms. Examples thereof include specificallymethoxy group, ethoxy group, propyloxy group, i-propyloxy group, butoxygroup, i-butoxy group, t-butoxy group, pentyloxy group, hexyloxy group,cyclohexyloxy group, heptyloxy group, octyloxy group, 2-ethylhexyloxygroup, nonyloxy group, deicyloxy group, 3,7-dimethyloctyloxy group,lauryloxy group etc. Among them, pentyloxy group, hexyloxy group,octyloxy group, 2-ethylhexyloxy group, decyloxy group, and 3,7-dimethyloctyloxy group are preferable.

The alkylthio group may be linear, branching or cyclic, and has usuallyabout one to 20 carbon atoms. Examples thereof include specificallymethylthio group, ethylthio group, propylthio group, and i-propylthiogroup, butylthio group, i-butylthio group, t-butylthio group, pentylthiogroup, hexylthio group, cyclohexylthio group, heptylthio group,octylthio group, 2-ethylhexylthio group, nonylthio group, decylthiogroup, 3,7-dimethyloctylthio group, laurylthio group etc. Among them,pentylthio group, hexylthio group, octylthio group, 2-ethylhexylthiogroup, decylthio group, and 3,7-dimethyloctylthio group are preferable.

The alkylsilyl group may be linear, branching or cyclic, and has usuallyabout one to 60 carbon atoms. Examples thereof include specificallymethylsilyl group, ethylsilyl group, propylsilyl group, andi-propylsilyl group, butylsilyl group, i-butylsilyl group, t-butylsilylgroup, pentylsilyl group, hexylsilyl group, cyclohexylsilyl group,heptylsilyl group, octylsilyl group, 2-ethylhexylsilyl group, nonylsilylgroup, decylsilyl group, 3,7-dimethyloctylsilyl group, laurylsilylgroup, trimethylsilyl group, ethyldimethylsilyl group,propyldimethylsilyl group, i-propyldimethylsilyl group,butyldimethylsilyl group, t-butyldimethylsilyl group,pentyldimethylsilyl group, hexyldimethylsilyl group, heptyldimethylsilylgroup, octyldimethylsilyl group, 2-ethylhexyldimethylsilyl group,nonyldimethylsilyl group, decyldimethylsilyl group,3,7-dimethyloctyl-dimethylsilyl group, lauryldimethylsilyl group, etc.Among them, pentylsilyl group, hexylsilyl group, octylsilyl group,2-ethylhexylsilyl group, decylsilyl group, 3,7-dimethyloctylsilyl group,pentyldimethylsilyl group, hexyldimethylsilyl group, octyldimethylsilylgroup, 2-ethylhexyl-dimethylsilyl group, decyldimethylsilyl group,3,7-dimethyloctyl-dimethylsilyl group are preferable.

The alkylamino group may be linear, branching or cyclic, and has usuallyabout one to 40 carbon atoms. Either monoalkylamino group ordialkylamino group may be available. Examples thereof includespecifically methylamino group, dimethylamino group, ethylamino group,diethylamino group, propylamino group, i-propylamino group, butylaminogroup, i-butylamino group, t-butylamino group, pentylamino group,hexylamino group, cyclohexylamino group, heptylamino group, octylaminogroup, 2-ethylhexylamino group, nonylamino group, decylamino group,3,7-dimethyloctylamino group, laurylamino group, etc. Among them,pentylamino group, hexylamino group, octylamino group, 2-ethylhexylaminogroup, decylamino group, and 3,7-dimethyloctylamino group arepreferable.

The aryl group has usually about 6 to 60 carbon atoms. Examples thereofinclude phenyl group, C₁₋₁₂ alkoxyphenyl group (C₁₋₁₂ means that thenumber of carbon atoms is from 1 to 12), C₁₋₁₂ alkylphenyl group,1-naphtyl group, 2-naphtyl group, etc. Among them, C₁₋₁₂ alkoxyphenylgroup, and C₁₋₁₂ alkylphenyl group are preferable.

The aryloxy group has usually about 6 to 60 carbon atoms. Examplesthereof include specifically, phenoxy group, C₁₋₁₂ alkoxyphenoxy group,C₁₋₁₂ alkylphenoxy group, 1-naphtyloxy group, 2-naphtyloxy group, etc.Among them, C₁₋₁₂alkoxyphenoxy group, and C₁₋₁₂ alkylphenoxy group arepreferable.

The arylalkyl group has usually about 7 to 60 carbon atoms. Examplesthereof include specifically, phenyl-C₁₋₁₂alkyl group, C₁₋₁₂alkoxyphenyl C₁₋₁₂alkyl group, C₁₋₁₂ alkylphenyl-C₁₋₁₂alkyl group,1-naphtyl-C₁₋₁₂alkyl group, 2-naphtyl-C₁₋₁₂ alkyl group, etc. Amongthem, C₁₋₁₂alkoxyphenyl-C₁₋₁₂alkyl group, andC₁₋₁₂alkylphenyl-C₁₋₁₂alkyl group are preferable.

The arylalkoxy group has usually about 7 to 60 carbon atoms. Examplesthereof include specifically, phenyl-C₁₋₁₂alkoxy group,C₁₋₁₂alkoxyphenyl-C₁₋₁₂alkoxy group, C₁₋₁₂alkylphenyl-C₁₋₁₂alkoxy group,1-naphtyl-C₁₋₁₂alkoxy group, 2-naphtyl-C₁₋₁₂alkoxy group, etc. Amongthem, C₁₋₁₂alkoxyphenyl-C₁₋₁₂alkoxy group, andC₁₋₁₂alkylphenyl-C₁₋₁₂alkoxy group are preferable.

The aryl alkenyl group has usually about 8 to 60 carbon atoms. Examplesthereof include specifically, cis-phenyl alkenyl group, trans-phenylalkenyl group, cis-tolyl alkenyl group, trans-tolyl alkenyl group,cis-1-naphtyl alkenyl group, trans-1-naphtyl alkenyl group,cis-2-naphtyl alkenyl group, trans-2-naphtyl alkenyl group, etc.

The aryl alkynyl group has usually about 8 to 60 carbon atoms. Examplesthereof include specifically, phenyl alkynyl group, tolyl alkynyl group,1-naphtyl alkynyl group, 2-naphtyl alkynyl group, etc.

The arylamino group has usually about 6 to 60 carbon atoms. Examplesthereof include specifically, diphenylamino group,C₁₋₁₂alkoxyphenylamino group, di(C₁₋₁₂alkoxyphenyl) amino group,di(C₁₋₁₂ alkylphenyl)amino group, 1-naphtylamino group, 2-naphtylaminogroup, etc. Among them C₁₋₁₂alkylphenylamino group, and di(C₁₋₁₂alkylphenyl)amino group are preferable.

The monovalent heterocyclic compound group means an atomic group of aheterocyclic compound in which one hydrogen atom is removed, and hasusually about 4 to 60 carbon atoms. Examples thereof include thienylgroup, C₁₋₁₂alkylthienyl group, pyroryl group, furyl group, pyridylgroup, C₁₋₁₂alkylpyridyl group, etc. Among them, thienyl group, C₁₋₁₂alkylthienyl group, pyridyl group, and C₁₋₁₂alkylpyridyl group arepreferable.

In order to improve the solubility of a polymeric light emittingsubstance in a solvent, it is suitable that at least one of thesubstituents contains an alkyl chain having cyclic or long chainstructure. Examples thereof include cyclopentyl group, cyclohexyl group,pentyl group, hexyl group, octyl group, 2-ethylhexyl group, decyl group,and 3,7-dimethyloctyl group. Two of the alkyl chain terminals may beconnected to form a ring. Moreover, a part of carbon atoms in the alkylchain may be substituted by a group containing hetero atom, and examplesof the hetero atom include an oxygen atom, a sulfur atom, a nitrogenatom, etc.

The aryl group and heterocyclic compound group in R may contain furtherone or more of substituents.

Complexes emitting triplet luminescence conventionally used are lowmolecular weight EL materials, which are disclosed in, for example:Nature, (1998), 395, 151; Appl. Phys. Lett. (1999), 75(1), 4; Proc.SPIE-Int. Soc. Opt. Eng. (2001), 4105 (Organic Light-Emitting Materialsand Devices IV), 119; J. Am. Chem. Soc.,(2001),123,4304; Appl. Phys.Lett., (1997), 71 (18), 2596; Syn. Met., (1998), 94 (1), 103; Syn. Met.,(1999), 99(2), 1361; and Adv. Mater., (1999), 11(10), 852.

The metal complex structure showing light emission from the tripletexcited state indicates a structure derived from the above-mentionedcomplex emitting triplet luminescence.

The polymeric light emitting substance having in the main chain a metalcomplex structure showing light emission from the triplet excited statemeans a case in which the main chain of the light emitting substance hasan aromatic ring or condensed ring thereof coordinated to a complexstructure showing light emission from the triplet excited state, or hasa metal.

The polymeric light emitting substance having in the side chain a metalcomplex structure showing light emission from the triplet excited statemeans a case in which an aromatic ring or condensed ring thereofcoordinated to a complex structure showing light emission from thetriplet excited state is connected to the main chain via an atom such asoxygen atom, sulfur atom, selenium atom, etc.; a direct bond such as asingle bond, and double bond; or a divalent group such as methylenegroup, alkylene group, arylene group, etc.

One example of the mode of the present invention is a polymeric lightemitting substance which contains two kinds or more of metal complexstructures showing light emission from the triplet excited state. Eachof the metal complex structures may have the same or different metals.Each of the metal complex structures may have the same or differentemitting colors. For example, a polymer may contain both of metalcomplex structures one of which emits green and the other emits red. Bydesigning the amount of the metal complex structures appropriately, theemitting color can be controlled, desirably.

In the polymeric light emitting substance of the present invention, themain chain preferably comprises a conjugated polymer.

Of polymeric light emitting substances of the present invention,preferable is a polymeric light emitting substance comprising one ormore repeating units of the general formula (1) and one or morerepeating units having a metal complex structure showing light emissionfrom the triplet excited state:

(wherein, Ar₁ represents an arylene group or a divalent heterocycliccompound group. R₁ and R₂ each independently represent a hydrogen atom,alkyl group, aryl group, monovalent heterocyclic compound group or cyanogroup, n represents 0 or 1).

Of them, a polymeric light emitting substance wherein the amount ofrepeating units having a metal complex structure showing light emissionfrom the triplet excited state is 0.01 molt or more and 10 molt or lessbased on the total amount of repeating units of the general formula (1)and repeating units having a metal complex structure showing lightemission from the triplet excited state, is more preferable. When theamount of repeating units having a metal complex structure showing lightemission from the triplet excited state is too large or too small, aneffect of high light emission efficiency tends to lower.

As the repeating unit having a metal complex structure showing lightemission from the triplet excited state, groups having bonding sites,remaining after removal of hydrogen atoms from the above-mentionedligand of the complex emitting triplet luminescence, are exemplified.

As the repeating unit having a metal complex structure showing lightemission from the triplet excited state, also listed are those in whichthe substituent of Ar₁ or, R₁ or R₂ in the above-mentioned repeatingunit of the formula (1) is a monovalent group having a metal complexstructure showing light emission from the triplet excited state.Preferable examples thereof are as follows.

R is the same as above.

The monovalent group having a metal complex structure showing lightemission from the triplet excited state is a group having one bondingsite, remaining after removal of one hydrogen atom from theabove-mentioned ligand of the complex emitting triplet luminescence.

The polymeric light emitting substance of the present invention may havea monovalent group in which the end of the main chain has a metalcomplex structure showing light emission from the triplet excited state.

In the general formula (1), Ar₁ means an arylene group or a divalentheterocyclic compound group. Ar₁ may have a substituent such as an alkylgroup, alkoxy group, alkylthio group, alkylsilyl group, alkylaminogroup, aryl group, aryloxy group, arylalkyl group, arylalkoxy group,alylalkenyl group, arylalkynyl group, arylamono group, monovalentheterocyclic compound group or cyano group. Examples of the substituentsare the same with the above R.

Ar₁ may be an arylene group or a divalent heterocyclic compound groupcontained in all materials conventionally used as an EL light emittingmaterial. Monomers which do not inhibit the triplet luminescence arepreferable. Examples of these materials are described in WO99/12989,WO00/55927, WO01/49769A1, WO01/49768A2, WO98/06773, U.S. Pat. No.5,777,070, WO99/54385, WO00/46321 and U.S. Pat. No. 6,169,163B1.

In the present invention, the arylene group means a divalent groupderived from an aromatic hydrocarbon having a benzene ring, a condensedring, and those in which independent benzene rings and/or condensedrings are bonded directly or through groups such as vinylene.

The arylene group has usually 6 to 60 carbon atoms, preferably 6 to 20.Examples thereof include: phenylene groups (for example, the belowstructures of Nos. 1 to 3), naphthalenediyl groups (the below structuresof Nos. 4 to 13), anthracenylene groups (the below structures of Nos. 14to 19), biphenylene groups (the below structures of Nos. 20 to 25),triphenylene groups (the below structures of Nos. 26 to 28),stilbene-diyl (the below structures of A to D), distilbene-diyl (thebelow structures of E and F), condensed-ring compound groups (the belowstructures of Nos. 29 to 38), etc. Here, the number of carbon atoms ofthe substituent is not counted as the number of carbon atoms of thearylene group.

The divalent heterocyclic compound group means an atomic group of aheterocyclic compound in which two hydrogen atoms are removed, and hasusually about 4 to 60, preferably 4 to 20 carbon atoms. Here, the numberof carbon atoms of the substituent is not counted as the number ofcarbon atoms of the divalent heterocyclic compound group.

Here, the heterocyclic compound means that an organic compound having acyclic structure in which at least one heteroatom such as oxygen,sulfur, nitrogen, phosphor, boron, etc. is contained in the cyclicstructure as the element other than carbon atoms.

Examples of the divalent heterocyclic compound group include thefollowings.

Divalent heterocyclic compound groups containing nitrogen as theheteroatom, such as: pyridine-diyl groups (the below structures of Nos.39 to 44), diazaphenylene groups (the below structures of Nos. 45 to48), quinolinediyl groups (the below structures of Nos. 49 to 63),quinoxalinediyl groups (the below structures of Nos. 64 to 68),acridinediyl groups (the below structures of Nos. 69 to 72),bipyridyldiyl groups (the below structures of Nos. 73 to 75),phenanthrolinediyl groups (the below structures of Nos. 76 to 78), etc.;groups having fluorene structure containing silicon, nitrogen, sulfur,selenium, etc. as the hetero atom (the below structures of Nos. 79 to93). In view of light emitting efficiency, preferable are carbazolesrepresented by formulae 82 to 84 containing a nitrogen atom or thosehaving an aromatic amine monomer such as triphenyldiyl.

Exemplified are 5-membered-ring heterocyclic compound groups containingsilicon, nitrogen, sulfur, selenium, etc. as the heteroatom (belowstructures of Nos. 94 to 98).

Exemplified are 5-membered-ring condensed heterocyclic compound groupscontaining silicon, nitrogen, sulfur, selenium, etc. as the heteroatom(below structures of Nos. 99 to 109), benzodiazole,benzooxadiazole-4,7-diyl, etc.

Exemplified are groups of 5-membered-ring heterocyclic compound groupscontaining silicon, nitrogen, sulfur, selenium, etc. as the heteroatomwhich form dimer or oligomer by bonding at á-position of the hetero atom(below structures of Nos. 110 to 118).

Exemplified are groups of 5-membered-ring heterocyclic compound groupscontaining silicon, nitrogen, sulfur, selenium, etc. as the heteroatomwhich bond to a phenyl group at á-position of the hetero atom (belowstructures of Nos. 112-118).

Here, R means a group as the same with those described above.

In the above formula (1), n is 0 or 1. R₁ and R₂ in formula (1)represent each independently a group selected from a hydrogen atom, analkyl group, an aryl group, a monovalent heterocyclic compound group,and a cyano group.

In the case where R₁ and R₂ are substituents other than a hydrogen atomor a cyano group, the alkyl group may be linear, branching or cyclic,and has usually about one to 20 carbon atoms. Examples thereof includespecifically methyl group, ethyl group, propyl group, butyl group,pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decylgroup, lauryl group, etc. Among them, methyl group, ethyl group, pentylgroup, hexyl group, heptyl group, and an octyl group are preferable.

The aryl group has usually about 6 to 60 carbon atoms. Examples thereofinclude specifically phenyl group, C₁₋₁₂ alkoxyphenyl group,C₁₋₁₂alkylphenyl group, 1-naphtyl group, 2-naphtyl group, etc. Amongthem, phenyl group and C₁₋₁₂ alkylphenyl group are preferable.

The monovalent heterocyclic compound group has usually about 4 to 60carbon atoms. Examples thereof include specifically thienyl group, C₁₋₁₂alkylthienyl group, pyroryl group, furyl group, pyridyl group, C₁₋₁₂alkylpyridyl group, etc. Among them, thienyl group, C₁₋₁₂ alkylthienylgroup, pyridyl group, and C₁₋₁₂ alkylpyridyl group are preferable.

In view of light emitting efficiency, it is suitable that one or more ofthe repeating units represented by the formula (2) below are containedas a repeating unit other than that represented by the above formula(1).

In the formula, Ar₂ and Ar₃ each independently represent an arylenegroup, or a divalent heterocyclic compound group. Ar₂ does notcross-link to Ar₃ R₁₁ represents an alkyl group, an aryl group, amono-valent heterocyclic comound group, a group represented by the belowformula (3) or (4). The symbol t is an integer from 1 to 4.

In the formula, Ar₄ is an arylene group or a divalent heterocycliccompound group. R₁ represents a hydrogen atom, an alkyl group, an arylgroup, mono-valent heterocyclic group, or a group represented by thebelow formula (4). Z₁₂ represents —CR₁₃═CR₁₄— or —C≡C—. R₁₃ and R₁₄ eachindependently represents a hydrogen atom, an alkyl group, an aryl group,mono-valent heterocyclic group, or cyano group. The symbol u is aninteger from 0 to 2.

In the formula, Ar₅ and Ar₆ each independently represents an arylenegroup or a divalent heterocyclic compound group. R₁₅ represents an alkylgroup, an aryl group, or mono-valent heterocyclic group. R₁₆ representsa hydrogen atom, an alkyl group, an aryl group, or mono-valentheterocyclic group. The symbol v is an integer from 1 to 4.

Examples of the arylene group and divalent heterocyclic compound groupin Ar₂ to Ar₆ include the same with those exemplified in the above Ar₁.

Examples of the alkyl group, aryl group and mono-valent heterocycliccompound group in R₁₁ to R₁₆ include the same with those exemplified inthe above R₁ or R₂.

Concrete examples of the repeating units represented by the aboveformula (2) are as follows.

R Is the same as above.

It is also suitable that one or more of the repeating units representedby the below formula (5) are contained as a repeating unit other thanthat represented by the above formula (1).

In the formula, R₁₁ means the same as above. R₁₈ and R₁₉ representsubstituents on aromatic ring. Examples thereof include a halogen atom,alkyl group, alkenyl group, aralkyl group, arylthio group, arylalkenylgroup, cyclic alkenyl group, alkoxy group, aryloxy group, alkyloxycarbonyl group, aralkyloxy carbonyl group, aryloxy carbonyl group, arylgroup, or mono-valent heterocyclic compound group. The symbols a and beach independently represent an integer from 0 to 3. When a or b is 2 ormore, R₁₈ and R₁₉ are the same or different mutually, which may beconnected to form a ring.

Examples of the mono-valent heterocyclic compound group, alkoxy groupinclude the same with those exemplified in the above R₁ and R₂.

Exemplified are: fluorine atom, chlorine atom, bromine atom and iodineatom as the halogen atom; methyl group, ethyl group, n-propyl group,iso-propyl group, n-butyl group, iso-butyl group, t-butyl group, n-amylgroup, noepentyl group, n-hexyl group, n-oxtyl group, n-nonyl group,2,3,4-trimethyl-3-pentyl group, 2,4-dimethyl-3-pentyl group, etc. as thealkyl group; 2-methyl-1-propenyl group and 2-butenyl group, etc. as thealkenyl group; benzyl group, 2-phenylethyl group, 2-naphthylethyl group,diphenylmethyl group, etc. as the aralkyl group; thiophenyl group, etc.as the arylthio group; trans-β-styryl group, 3-phenyl-1-propenyl group,etc. as the arylalkenyl group; 1-cyclohexenyl group, etc. as the cyclicalkenyl group; methoxy group, ethoxy group, n-propoxy group, t-butoxygroup, etc. as the alkoxy group; phenoxy group, naphthyloxy group,diphenyloxy group, etc. as the aryloxy group; methoxy carbonyl group,ethoxy carbonyl group, t-butyloxy carbonyl group, etc. as the alkyoxycarbonyl group; benzyloxy carbonyl group, etc. as the aralkyloxycarbonyl group; phenyloxy carbonyl group, etc. as the aryloxy carbonylgroup; pheny group, naphtyl group, biphenyl group, furyl group, etc. asthe aryl group.

A protecting group may be used to stabilize the terminal group of apolymeric light emitting substance in accordance with the presentinvention since if an active polymerizable group remains intact, thereis a possibility of reduction of the light emitting property and life ofthe polymeric light emitting substance when the material is used in adevice. Groups having a conjugated bond continued to the conjugatedstructure of the main chain are preferable, and examples thereof includestructures containing a bond to an aryl group or a heterocyclic compoundgroup via a vinylene group. Specifically, substituents described in JP-ANo. 9-45478, chemical formula 10, and the like are exemplified.

The polymeric light emitting substance of the present invention may alsocontain repeating units other than the repeating unit of the generalformula (1) and the repeating unit having a metal complex structureshowing light emission from the triplet excited state, in an amount notdeteriorating light emission property and charge transfer property.Further, the repeating unit of the general formula (1), the repeatingunit having a complex structure showing light emission from the tripletexcited state, and other repeating units may be connected in the form ofnon-conjugated units, or these non-conjugated parts may be contained inthe repeating units. As the bonding structure, there are exemplified thefollowing structures, combinations of the following structures with avinylene group, combinations of two or more of the following structures,and the like. Here, R is a group selected from the same substituents asdescribed above, and Ar represents a hydrocarbon group having 6 to 60carbon atoms.

In the polymeric light emitting substance of the present invention, theamount of the repeating units having a metal complex structure showinglight emission from the triplet excited state is 0.01 molt or more and10 molt or less based on the total amount of the repeating units of thegeneral formulas (1), (2) and (5), and the repeating units having ametal complex structure showing light emission from the triplet excitedstate.

The polymeric light emitting substance of the present invention ischaracterized by emitting the light from the complex of the belowformula (6):

In the formula, M represents a metal atom having an atomic number of 50or more and showing a possibility of the intersystem crossing betweenthe singlet state and the triplet state in this complex by aspin-orbital mutual action. Ar represents a ligand bonded to M, via oneor more of a nitrogen atom, oxygen atom, carbon atom, sulfur atom andphosphorus atom, with bonding to a polymer at an arbitrary position. Lrepresents a hydrogen atom, hydrocarbon group having 1 to 10 carbonatoms, carboxylate group having 1 to 10 carbon atoms, diketonate grouphaving 1 to 10 carbon atoms, halogen atom, amide group, imide group,alkoxide group, alkylmercapto group, carbonyl ligand, arylene ligand,alkene ligand, alkyne ligand, amine ligand, imine ligand, nitrileligand, isonitrile ligand, phosphine ligand, phosphine oxide ligand,phosphite ligand, ether ligand, sulfone ligand, sulfoxide ligand orsulfide ligand, m represents an integer of 1 to 5. o represents aninteger of 0 to 5.

As the halogen atom represented by X, iodine, bromine, chlorine and thelike are exemplified. As the arylsulfonyloxy group, apentafluorophenylsulfonyloxy group, p-toluenesulfonyloxy group and thelike are exemplified, and as the alkylsulfonyloxy group, amethanesulfonyloxy group, trifluoromethanesulfonyloxy group and the likeare exemplified.

Of them, M is preferably rhenium atom, osmium atom, iridium atom,platinum atom, samarium atom, europium atom, gold atom, gadolinium atom,terbium atom or dysprosium atom, more preferably iridium atom, platinumatom, or gold atom, and further preferably iridium atom.

Ars are the same or different mutually and represent a ligand bonded toM, via one or more of a nitrogen atom, oxygen atom, carbon atom, sulfuratom and phosphorus atom, with bonding to a polymer at an arbitraryposition.

Of them, it is preferable that Ar is a tetra-dentate ligand bonded to M,via any four atoms of a nitrogen atom, oxygen atom, carbon atom, sulfuratom and phosphorus atom. For example, as a ligand in which four pyrrolerings are connected in the form of ring,7,8,12,13,17,18-hexakisethyl-21H,23H-porphyrin is specifically listed.

Further, it is also that Ar is a bidentate ligand forming a 5-memberedring by bonding to M, via any two atoms of a nitrogen atom, oxygen atom,carbon atom, sulfur atom and phosphorus atom.

It is more preferable that M bonds to at least one carbon atom and Ar isbidentate ligand represented by the below formula

In the formula, R³ to R¹⁰ represent halogen atom, alkyl group, alkenylgroup, aralkyl group, arylthio group, arylalkenyl group, cyclic alkenylgroup, alkoxy group, aryloxy group, alkyloxy carbonyl group, aralkyloxycarbonyl group, aryloxy carbonyl group, or aryl group. At least one ofR³ to R¹⁰ is a bonding group to a polymer chain.

As Ar, exemplified are ligands constituted by connecting heterocyclicrings such as a pyridine ring, thiophene ring, benzooxazole ring and thelike, and a benzene ring, and specific examples thereof includephenylpyridine, 2-(p-phenylphenyl)pyridine, 7-bromobenzo[h]quinoline,2-(4-thiophen-2-yl)pyridine, 2-(4-phenylthiophen-2-yl)pyridine,2-phenylbenzooxazole, 2-(p-phenylphenyl)benzooxazole,2-phenylbenzothiazole, 2-(p-phenyphenyl)benzothiazole,2-(benzohiophen-2-yl)pyridine and the like, which may have one or moresubstituents.

As the substituents of Ar, exemplified are a halogen atom, alkyl group,alkenyl group, aralkyl group, arylthio group, arylalkenyl group, cyclicalkenyl group, alkoxy group, aryloxy group, alkyloxy carbonyl group,aralkyloxy carbonyl group, aryloxy carbonyl group, aryl group, ormono-valent heterocyclic compound group. Concrete examples are the sameas those represented in R₁₈ and R₁₉.

Examples of L in the general formula (6) include: methyl group, ethylgroup, propyl group, butyl group, cyclohexyl group as the alkyl group;phenyl group, tolyl group, 1-naphtyl group, 2-naphtyl group, etc. as thearyl group; and phenylpyridine, 2-(p-phenylphenyl)pyridine,7-bromobenzo[h]quinoline, 2-(4-thiophen-2-yl)pyridine,2-(4-phenylthiophen-2-yl)pyridine, 2-phenylbenzooxazole,2-(p-phenylphenyl)benzooxazole, 2-phenylbenzothiazole,2-(p-phenyphenyl)benzothiazole, 2-(benzohiophen-2-yl)pyridine, etc. asthe heterocyclic compound group.

The carboxylate group having 1 to 10 carbon atoms is not particularlyrestricted, and examples thereof include an acetate group, naphthenategroup, 2-ethylhexanoate group and the like. As the diketonate grouphaving 1 to 10 carbon atoms is not particularly restricted, and examplesthereof include an acetylacetonate group and the like. The halogen atomis not particularly restricted, and examples thereof include a fluorineatom, chlorine atom, bromine atom, iodine atom and the like. The amidegroup is not particularly restricted, and examples thereof include adimethylamide group, diethylamide group, diisopropylamide group,dioctylamide group, didecylamide group, didodecylamide group,bis(trimethylsilyl)amide group, diphenylamide group, N-methylanilide,anilide group and the like. The imide group is not particularlyrestricted, and examples thereof include a benzophenoneimide and thelike. The alkoxy group is not particularly restricted, and examplesthereof include a methoxide group, ethoxide group, propoxide group,butoxide group, phenoxide group and the like. The alkylmercapto group isnot particularly restricted, and examples thereof include amethylmercapto group, ethylmercapto group, propylmercapto group,butylmercapto group, phenylmercapto group and the like. The arene ligandis not particularly restricted, and examples thereof include benzene,toluene, xylene, trimethylbenzene, hexamethylbenzene, naphthalene andthe like. The alkene ligand is not particularly restricted, and examplesthereof include ethylene, propylene, butene, hexene, decene and thelike. The alkyne ligand is not particularly restricted, and examplesthereof include acetylene, phenylacetylene, diophenylacetylene and thelike. The amine ligand is not particularly restricted, and examplesthereof include triethylamine, tributylamine and the like. The imineligand is not particularly restricted, and examples thereof include abenzophenoneimine, methylethylimine and the like. The nitrile ligand isnot particularly restricted, and examples thereof include acetonitrile,benzonitrile and the like. The isonitrile is not particularlyrestricted, and examples thereof include t-butylisonitrile,phenylisonitrile and the like. The phosphine ligand is not particularlyrestricted, and examples thereof include triphenylphosphine,tritolylphosphine, tricyclohexylphosphine, tributylphosphine and thelike. The phosphine oxide ligand is not particularly restricted, andexamples thereof include tributylphosphine oxide, triphenylphosphineoxide and the like. The phosphite ligand is not particularly restricted,and examples thereof include triphenylphosphite, tritolylphosphite,tributylphosphite, triethylphosphite and the like. The ether ligand isnot particularly restricted, and examples thereof include dimethylether, diethylether, tetrahydrofuran and the like. The sulfone ligand isnot particularly restricted, and examples thereof includedimethylsulfone, dibutylsulfone and the like. The sulfoxide ligand isnot particularly restricted, and examples thereof includedimethylsulfoxide, dibutylsulfoxide and the like. The sulfide ligand isnot particularly restricted, and examples thereof include ethyl sulfide,butyl sulfide and the like.

The above-mentioned polymeric light emitting substance may be a random,block or graft copolymer, or a polymer having an intermediate structureof them, for example, a random copolymer having a property of block.From the standpoint of obtaining a polymeric light emitting substancehaving high quantum yield of light emission, a random copolymer having aproperty of block, and a block or graft copolymer is preferable, ratherthan a complete random copolymer.

As this polymeric light emitting substance, those showing light emissionin solid state are suitably used, due to utilization of light emissionfrom a thin film.

As the good solvent for the above-mentioned polymeric light emittingsubstance, chloroform, methylene chloride, dichloroethane,tetrahydrofuran, toluene, xylene, mesitylene, tetralin, decalin,n-butylbenzene and the like are exemplified. Depending on the structureand molecular weight of a polymeric light emitting substance, thepolymeric light emitting substance can be usually dissolved in thesesolvents in an amount of 0.1% by weight or more.

The polymeric light emitting substance of the present invention has apolystyrene reduced number-average molecular weight of from 10³ to 10⁸.The total number of the repeating structures varies also depending onthe repeating structure and ratio thereof. From the standpoint of filmformation property, it is generally that the total number of repeatingunits is preferably from 20 to 10000, further preferably from 30 to10000, particularly preferably from 50 to 5000.

When the polymeric light emitting substance of the present invention isused as a light emitting material of a polymer LED, it is preferable toconduct polymerization after purification of a monomer beforepolymerization, by methods such as distillation, sublimationpurification, re-crystallization and the like, since the purity thereofexert an influence on light emitting property, and it is preferable toeffect purification treatment such as re-precipitation purification,chromatography fractionation and the like, after synthesis.

The polymeric light emitting substance of the present invention can beproduced by polymerization using as a raw material a monomer having apolymerization active group derived from the complex emitting tripletluminescence. When there is a possibility of decomposition of a monomerhaving a polymerization active group derived from the complex emittingtriplet luminescence, under polymerization conditions, it may also bepermissible that polymerization is conducted using as a raw material amonomer having a polymerization active group derived from the complexemitting triplet luminescence, to obtain a polymer, and this polymer isreacted with a center metal of the complex emitting tripletluminescence.

As the polymerization active group use here, there are listed, forexample, a formyl group, phosphonium group, halogen groups such asbromine, iodine, chlorine and the like, vinyl group, halomethyl group,acetonitrile group, alkylsulfonyloxy groups such as atrifluoromethanesulfonyloxy group and the like, arylsulfonyloxy groupssuch as a toluenesulfonyloxy group and the like, though varyingdepending on the polymerization method.

The polymeric light emitting substance of the present invention can beproduced by polymerization using a monomer having a polymerizationactive group derived from the complex emitting triplet luminescence and,if necessary, other monomers as raw materials, according to JP-A No.5-202355, for example.

Namely, exemplified are:

-   [1] a polymerization of a compound having aldehyde group with a    compound having phosphonium salt group according to Wittig reaction;-   [2] a polymerization of a compound having aldehyde group and    phosphonium salt group according to Wittig reaction;-   [3] a polymerization of a compound having vinyl group with a    compound having halogen group according to Heck reaction;-   [4] a polymerization of a compound having vinyl group and halogen    group according to Heck reaction;-   [5] a polymerization of a compound having aldehyde group with a    compound having alkyl phosphonate group according to    Horner-Wadsworth-Emmons method;-   [6] a polymerization of a compound having aldehyde group and alkyl    phosphonate group according to Horner-Wadsworth-Emmons method;-   [7] a polycondensation of a compound having two methyl halide groups    according to de-hydrohalogenation method;-   [8] a polycondensation of a compound having two sulfonium salt    groups according to the sulfonium salt decomposing method;-   [9] a polymerization of a compound having aldehyde group with a    compound having acetonitrile group according to Knoevenagel    reaction;-   [10] a polymerization of a compound having aldehyde group and    acetonitrile group according to Knoevenagel reaction; and-   [11] a polymerization of a compound having two or more aldehyde    groups according to the McMurry reaction.    The polymerizations [1] to [11] are shown as follows.

When a vinylene group is not contained in the main chain, there areexemplified methods in which polymerization is effected with using amonomer having a polymerizable group derived from a complex emittingtriplet luminescence, and if necessary, using another monomer:

-   [12] a method of polymerization according to a Suzuki coupling    reaction,-   [13] a method of polymerization according to a Grignard reaction,-   [14] a method of polymerization using a Ni(O) catalyst,-   [15] a method of polymerization using an oxidizing agent such as    FeCl₃ and the like, a method of oxidation polymerization    electrochemically,-   [16] a method according to decomposition of an intermediate polymer    having a suitable releasing group, and the like.    The polymerization methods [12] to [16] are shown as follows.

Among the above, methods of effecting polymerization according to Wittigreaction, Heck reaction, Horner-Wadsworth-Emmons method, Knoevenagelreaction, Suzuki coupling reaction, Grignard reaction, and apolymerization using a Ni(O) catalyst are suitable since reactioncontrol is easy. In view of the availability of the raw materials andsimple operationality of the polymerization reaction, polymerizationsaccording to Suzuki coupling reaction or Grignard reaction, and apolymerization using a Ni(O) catalyst are preferable.

Monomers can be reacted with dissolving in a solvent if necessary, withusing an appropriate catalyst such as, for example, an alkali, and at atemperature of above the melting point and below the boiling point ofthe organic solvent. Known methods can be used as described in: OrganicReactions, volume 14, pages 270-490, (John Wiley & Sons, Inc., 1965);Organic Reactions, volume 27, pages 345-390 (John Wiley & Sons, Inc.,1982); Organic Synthesis, Collective Volume VI, pages 407-411 (JohnWiley & Sons, Inc., 1988); Chemical Review, volume 95, page 2457 (1995);J. Organomet. Chem., volume 576, page 147 (1999); J. Prakt. Chem.,volume 336, page 247 (1994); and Makromol. Chem. Macromol. Symp., volume12, page 229 (1987).

Though the organic solvent varies also depending on compounds andreactions used, it is generally preferable that de-oxygen treatment issufficiently performed on the solvent used and the reaction thereof isallowed to progress under an inert atmosphere, to suppress a sidereaction. Further, it is preferable to conduct dehydration treatmentlikewise (however, this is not applicable in the case of a reaction in atwo-phase system with water, such as a Suzuki coupling reaction.).

An alkali and a suitable catalyst are added appropriately forprogressing a reaction. These may advantageously be selected dependingon the reaction used. It is preferable that this alkali or catalyst issufficiently dissolved in a solvent used for the reaction. As the methodof mixing an alkali or catalyst, there is exemplified a method in whicha solution of an alkali or catalyst is added slowly while stirring thereaction solution under an inert atmosphere such as argon, nitrogen andthe like, or the reaction solution is added slowly to the solution of analkali or catalyst, conversely.

In the method of producing a polymeric light emitting substance of thepresent invention, monomers may be mixed and reacted at one time, ormixed divisionally, if necessary.

Regarding more specific reaction conditions in the case of a Wittigreaction, Horner reaction, Knoevengel reaction and the like, an alkaliis used in an equivalent amount or more, preferably from 1 to 3equivalent based on the functional group of a monomer, and reacted. Thealkali is not particularly restricted, and there can be used, forexample, potassium-t-butoxide, sodium-t-butoxide, metal alcolates suchas sodium ethylate, lithium methylate and the like, hydride reagentssuch as sodium hydride and the like, amide such as sodiumamide and thelike. As the solvent, N,N-dimethylformadide, tetrahydrofuran, dioxane,toluene and the like are used. The temperature for the reaction isusually from room temperature to about 150° C. The reaction time is, forexample, from 5 minutes to 40 hours, and time for sufficient progress ofpolymerization may be permissible, and there is no necessity of leavingfor along period of rime after completion of the reaction, therefore,the reaction time is from 10 minutes to 24 hours. The concentration inthe reaction may be appropriately selected in the range from about 0.01wt % to the maximum solution concentration, since reaction efficiency ispoor when too thin and reaction control is difficult when too thick, andusually is in the range from 0.1 wt % to 20 wt %. In the case of a Heckreaction, monomers are reacted in the presence of a base such astriethylamine and the like, using a palladium catalyst. A solvent havinga relatively high boiling point such as N,N-dimethylformamide,N-methylpyrrolidone and the like is used, the reaction temperature isfrom about 80 to 160%, and the reaction time is from about 1 hour to 100hours.

In the case of a Suzuki coupling reaction,palladium[tetrakis(triphenylphosphine)], palladium acetates and thelike, for example, are used, and an inorganic base such as potassiumcarbonate, sodium carbonate, barium hydroxide and the like, an organicbase such as triethylamine and the like, and an inorganic salt such ascesium fluoride and the like are added in an amount of equivalent ormore, preferably from 1 to 10 equivalent based on monomers, and reacted.An inorganic salt may be reacted in the form of an aqueous solution, ina two-phase system. As the solvent, N,N-dimethylformamide, toluene,dimethoxyethane, tetrahydrofuran and the like are exemplified. Thoughdepending on the solvent, a temperature of from about 50 to 160° C. ispreferably used. It may also be permissible to heat the reactionsolution to a temperature near the boiling point of the solvent, tocause reflux. The reaction time is from about 1 hour to 200 hours.

In the case of a Grignard reaction, a method is exemplified in which ahalogenated compound and metal Mg are reacted in an ether-based solventsuch as tetrahydrofuran, diethyl ether, dimethoxyethane and the like toprepare a Grignard reagent solution which is mixed with a monomersolution prepared separately, and a nickel or palladium catalyst isadded while paying attention to excess reaction to the resulted mixturewhich is then heated to cause a reaction under reflux. A Grignardreagent is used in equivalent or more, preferably from 1 to 1.5equivalent, more preferably from 1 to 1.2 equivalent based on monomers.Also in the case of polymerization by methods other than this, thereaction can be conducted according to known methods.

The method of producing a polymeric light emitting substance of thepresent invention is a production method, comprising reacting a monomerof X₁—A—X₂ (wherein, X₁ and X₂ each independently represent a halogenatom, alkylsulfonyloxy group or arylsulfonyloxy group. —A— represents arepeating unit having a metal complex structure showing light emissionfrom the triplet excited state.) with X₃—Ar₁—X₄ (wherein, X₃ and X₄ eachindependently represent a halogen atom, alkylsulfonyloxy group orarylsulfonyloxy group.) in the presence of a Ni catalyst.

Another method of producing a polymeric light emitting substance of thepresent invention is a production method, comprising reacting a monomerof Y₁—A—Y₂ (wherein, Y₁ and Y₂ each independently represent a boric acidgroup or borate group.) with a monomer of Z₁—Ar—Z₂ (wherein, Z₁ and Z₂represent a halogen atom, alkylsulfonyloxy group or arylsulfonyloxygroup.) in the presence of a Pd catalyst.

Still another method of producing a polymeric light emitting substanceof the present invention is a production method, comprising reacting amonomer of Y₃—Ar₁—Y₄ (wherein, Y₃ and Y₄ each independently represent aboric acid group or borate group.) with a monomer of Z₃—A—Z₄ (wherein,Z₃ and Z₄ each independently represent a halogen atom, alkylsulfonyloxygroup or arylsulfonyloxy group.) in the presence of a Pd catalyst.

Particularly, the amount of a monomer of X₁—A—X₂, a monomer of Y₁—A—Y₂,or a monomer of Z₃—A—Z₄, is from 0.01 molt or more and 10 mol % or lessbased on the total amount of monomers.

By method of producing a polymeric light emitting substance of thepresent invention, a polymeric light emitting substance having in themain chain or side chain of the polymer a metal complex structureshowing light emission from the triplet excited state can be easilysynthesized, leading to a significant industrial advantage.

In the above-mentioned polymers, —A— represents a repeating unit havinga metal complex structure showing light emission from the tripletexcited state, and specifically, there are listed divalent groups inwhich any two of Rs in above-exemplified complex emitting tripletluminescence are bonding sites with the adjacent repeating unit.

As the halogen atom represented by X₁, X₂, X₃, X₄, Z₁, Z₂, Z₃ and Z₄,iodine, bromine, chlorine and the like are exemplified. As thearylsulfonyloxy group, a pentafluorophenylsulfonyloxy group,p-toluenesulfonyloxy group and the like are exemplified, and as thealkylsulfonyloxy group, a methanesulfonyloxy group,trifluoromethanesulfonyloxy group and the like are exemplified.

As the boric acid group and borate group represented by Y₁, Y₂, Y₃ andY₄, a boric acid group, dimethyl borate, ethylene borate, trimethyleneborate and the like are exemplified.

As the example of reaction in the presence of a Ni catalyst, a method ofpolymerization using the above-mentioned Ni(O) catalyst is exemplified.

As the nickel catalyst, an ethylenebis(triphenylphosphine)nickelcomplex, tetrakis(triphenylphosphine)nickel complex,bis(cyclooctadienyl)nickel complex, and the like, are exemplified.

As the example of reaction in the presence of a Pd catalyst, theabove-mentioned Suzuki coupling reaction is exemplified.

As the palladium catalyst, palladium acetate, palladium[tetrakis(triphenylphosphine)] complex,bis(tricyclohexylphosphine)palladium complex, and the like, areexemplified.

The complex of the present invention will be described below.

The complex of the present invention has a ligand carrying a bromineatom, chlorine atom, iodine atom, arylsulfonyloxy group,alkylsulfonyloxy group and the like as a reactive functional group, andis a novel complex having iridium, platinum, europium or gold as acenter metal, and a complex which can be a monomer, a raw material ofthe polymeric light emitting substance of the present invention. Thiscomplex solves a problem that the above-mentioned known complex has noreactive functional group, and it is difficult to convert the complexinto a derivative or to use the complex as a monomer for polymersynthesis.

The complex of the present invention is a complex of the general formula(8):

In the formula, L, M, Ar, m and o are the same as those described above.X represents a halogen atom, arylsulfonyloxy group or alkylsulfonyloxygroup.

As the halogen atom represented by X, iodine, bromine, chlorine and thelike are exemplified. As the arylsulfonyloxy group, apentafluorophenylsulfonyloxy group, p-toluenesulfonyloxy group and thelike are exemplified, and as the alkylsulfonyloxy group, amethanesulfonyloxy group, trifluoromethanesulfonyloxy group and the likeare exemplified.

Of them, preferable is the complex wherein when energies of the singletstate and the triplet state of the complex of the formula (8) in whichall Xs represent a hydrogen atom are calculated by a B3LYP method, thedifferent between the energies of the singlet state and the tripletstate is 6 eV or less. This difference is preferably 4 eV or less,further preferably 2 eV or less.

Particularly, complexes of the general formula (9) is preferable.M′(Ar′)_(q)(L′)r  (9)In the formula, M′ represents an iridium atom, platinum atom or goldatom. Ar's are the same or different and represent a bidentate ligandforming a 5-membered ring by bonding to M′, via a nitrogen atom andcarbon atom, the bidentate ligand containing at least one bromine atom.L's each independently represent a hydrogen atom, alkyl group, arylgroup, heterocyclic compound group, hydrocarbon group having 1 to 10carbon atoms, carboxylate group having 1 to 10 carbon atoms, diketonategroup having 1 to 10 carbon atoms, halogen atom, amide group, imidegroup, alkoxide group, alkylmercapto group, carbonyl ligand, aryleneligand, alkene ligand, alkyne ligand, amine ligand, imine ligand,nitrile ligand, isonitrile ligand, phosphine ligand, phosphine oxideligand, phosphite ligand, ether ligand, sulfone ligand, sulfoxide ligandor sulfide ligand. q represents an integer of 1 to 3. r represents aninteger of 0 to 2.

Specific examples of the ligand Ar′ of the complex of the generalformula (9) include, when represented in the form (Ar′H) in which ahydrogen atom is added to a carbon atom bonded to M,2-m-bromophenylpyridine, 2-(m-bromo-p-phenylphenyl)pyridine,7-bromobenzo[h]quinoline, 2-(5-bromo-4-thiophen-2-yl)pyridine,2-(5-bromo-4-phenylthiophen-2-yl)pyridine, 2-m-bromophenylbenzooxazole,2-(m-bromo-p-phenylphenyl)benzooxazole, 2-m-bromophenylbenzothiazole,2-(m-bromo-p-phenylphenyl)benzothiazole,2-(6-bromobenzothiophen-2-yl)pyridine,2-bromo-7,8,12,13,17,18-hexakisethyl-21H,23H-porphyrin,6-bromo-1,10-phenanethroline, benzoyl-p-bromobenzoyl-methane,(4-bromothenoyl)trifluoroacetone and the like, and preferable are2-m-bromophenylpyridine, 7-bromobenzo[h]quinoline,2-m-bromophenylbenzooxazole, 2-m-bromophenylbenzothiazole and the like.

The ligand Ar′ of the complex of the general formula (9) may have asubstituent such as a halogen atom, alkyl group, alkenyl group, aralkylgroup, arylthio group, arylalkenyl group, cyclic alkenyl group, alkoxygroup, aryloxy group, alkyloxycarbonyl group, aralkyloxycarbonyl group,aryl group and the like.

Specific examples of the substituent represented by Ar′ are as follows.

As the halogen atom, a fluorine atom, chlorine atom, bromine atom,iodine atom and the like are listed, as the alkyl group, a methyl, ethylgroup, n-propyl group, isopropyl group, n-butyl group, isobutyl group,t-butyl group, n-amyl group, neopentyl group, n-hexyl group, cyclohexylgroup, n-octyl group, n-nonyl group, 2,3,4-trimethyl-3-pentyl group,2,4-dimethyl-3-pentyl group and the like are listed, as the alkenylgroup, a 2-methyl-1-propenyl group, 2-butenyl group and the like arelisted, as the aralkyl group, a benzyl group, 2-phenylethyl group,2-naphtylethyl group, diphenylmethyl group and the like are listed, asthe arylthio group, a thiophenyl group and the like are listed, as thearylalkenyl group, a trans B styryl group, 3-phenyl-1-propenyl group andthe like are listed, as the cyclic alkenyl group, a 1-cyclohecenyl groupand the like are listed, as the alkoxy group, a methoxy group, ethoxygroup, n-propoxy group, t-butoxy group and the like are listed, as thearyloxy group, a phenoxy group, naphthyloxy group, diphenyloxy group andthe like are listed, as the alkyloxycarbonyl group, a methoxycarbonylgroup, ethoxycarbonyl group, t-butyloxycarbonyl group, as thearalkyloxycarbonyl group, a benzyloxycarbonyl group and the like arelisted, as the aryloxycarbonyl group, a phenyloxycarbonyl and the likeare listed, and as the aryl group, a phenyl group, naphthyl group,biphenyl group, furyl group and the like are listed, respectively.

The above-mentioned substituents other than halogen atoms may besubstituted with, for example, halogen atoms such as a fluorine atom,chlorine atom, bromine atom, iodine atom and the like; alkoxy groupssuch as a methoxy group, ethoxy group, n-propoxy group, t-butoxy groupand the like; aryloxy groups such as a phenoxy group and the like; loweralkyl groups such as a methyl group, ethyl group, n-propyl group,isopropyl group, n-butyl group, isobutyl group, t-butyl group, n-amylgroup, neopentyl group, n-hexyl group and the like; lower alkylthiogroups such as a n-propylthio group, t-butylthio group and the like;arylthio groups such as a phenylthio group, and a nitro group, hydroxylgroup and the like.

The hydrocarbon group having 1 to 10 carbon atoms represented by L inthe general formula (8) and L′ in the general formula (9) is notparticularly restricted, and examples thereof include a methyl group,ethyl group, propyl group, butyl group, cyclohexyl group, benzyl group,phenyl group and the like. The carboxylate group having 1 to 10 carbonatoms is not particularly restricted, and examples thereof include anacetate group, naphthenate group, 2-ethylhexanoate group and the like.As the diketonate group having 1 to 10 carbon atoms is not particularlyrestricted, and examples thereof include an acetylacetonate group andthe like. The halogen atom is not particularly restricted, and examplesthereof include a fluorine atom, chlorine atom, bromine atom, iodineatom and the like. The amide group is not particularly restricted, andexamples thereof include a dimethylamide group, diethylamide group,diisopropylamide group, dioctylamide group, didecylamide group,didodecylamide group, bis(trimethylsilyl)amide group, diphenylamidegroup, N-methylanilide, anilide group and the like. The imide group isnot particularly restricted, and examples thereof include abenzophenoneimide and the like. The alkoxy group is not particularlyrestricted, and examples thereof include a methoxide group, ethoxidegroup, propoxide group, butoxide group, phenoxide group and the like.The alkylmercapto group is not particularly restricted, and examplesthereof include a methylmercapto group, ethylmercapto group,propylmercapto group, butylmercapto group, phenylmercapto group and thelike. The arylene group is not particularly restricted, and examplesthereof include benzene, toluene, xylene, trimethylbenzene,hexamethylbenzene, naphthalene and the like. The alkene ligand is notparticularly restricted, and examples thereof include ethylene,propylene, butene, hexene, decene and the like. The alkyne ligand is notparticularly restricted, and examples thereof include acetylene,phenylacetylene, diophenylacetylene and the like. The amine ligand isnot particularly restricted, and examples thereof include triethylamine,tributylamine and the like. The imine ligand is not particularlyrestricted, and examples thereof include a benzophenoneimine,methylethylimine and the like. The nitrile ligand is not particularlyrestricted, and examples thereof include acetonitrile, benzonitrile andthe like. The isonitrile is not particularly restricted, and examplesthereof include t-butylisonitrile, phenylisonitrile and the like. Thephosphine ligand is not particularly restricted, and examples thereofinclude triphenylphosphine, tritolylphosphine, tricyclohexylphosphine,tributylphosphine and the like. The phosphine oxide ligand is notparticularly restricted, and examples thereof include tributylphosphineoxide, triphenylphosphine oxide and the like. The phosphate ligand isnot particularly restricted, and examples thereof includetriphenylphosphite, tritolylphosphite, tributylphosphite,triethylphosphite and the like. The ether ligand is not particularlyrestricted, and examples thereof include dimethyl ether, diethylether,tetrahydrofuran and the like. The sulfone ligand is not particularlyrestricted, and examples thereof include dimethylsulfone,dibutylsulfone-and the like. The sulfoxide ligand is not particularlyrestricted, and examples thereof include dimethylsulfoxide,dibutylsulfoxide and the like. The sulfide ligand is not particularlyrestricted, and examples thereof include ethyl sulfide, butyl sulfideand the like.

Specific examples of the complex (9) of the present invention include,regarding those containing an iridium atom as a center metal M′ forexample, tris(2-m-bromophenylpyridine)iridium (III),bis(2-m-bromophenylpyridine)(phenylpyridine)iridium (III),(2-m-bromophenylpyridine)di(phenylpyridine)iridium (III),bis(7-bromobenzo[h]quinoline)acetylacetonate iridium(III),bis{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate iridium(III), bis(2-(3-bromophenyl)benzooxazole)acetylacetonate iridium (III),bis(2-(3-bromophenyl)benzothiazole)acetylacetonate iridium (III),bis{2-(5-bromobenzothiophen-2-yl)pyridine}acetylacetonate iridium (III)and the like.

Examples of the complex (3) of the present invention include, regardingthose containing a platinum atom as a center metal M′,bis(2-m-bromophenylpyridine)platinum(II),(2-m-bromophenylpyridine)(phenylpyridine)platinum (II),(7-bromobenzo[h]quinoline)acetylacetonate platinum(II),{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate platinum (II),(2-(3-bromophenyl)benzooxazole)acetylacetonate platinum (II),(2-(3-bromophenyl)benzothiazole)acetylacetonate platinum (II),{2-(5-bromobenzothiophen-2-yl)pyridine}acetylacetonate platinum (II) andthe like.

Examples of the complex (3) of the present invention include, regardingthose containing a gold atom as a center metal M′,tris(2-m-bromophenylpyridine)(phenylpyridine)gold (III),bis(2-m-bromophenylpyridine)(phenylpyridine) gold (III),(2-m-bromophenylpyridine)di(phenylpyridine) gold (III),bis(7-bromobenzo[h]quinoline)acetylacetonate gold (III),bis{2-(5-bromothiophen-2-yl)pyridine}acetylacetonate gold (III),bis(2-(3-bromophenyl)benzooxazole)acetylacetoante gold (III),bis(2-(3-bromophenyl)benzothiazole)acetylacetonate gold (III),bis{2-(5-bromobenzothiophen-2-yl)pyridine}acetylacetonate gold (III) andthe like.

Examples of the complex (3) of the present invention include, regardingthose containing an europium atom as a center metal M′,(6-bromo-1,10-phenanethroline)tris(dibenzoylmethane)europi um (III),(6-bromo-1,10-phenanathroline)tris[(4-bromothenoyl)trifluoroacetone]europium (III), and the like.

Of them, those in which Ar′ is a bidentate ligand of the general formula(10) and r is 0 are preferable, those in which one or more of R²¹ to R²⁸represent a bromine atom are more preferable, those in which R²³represents a bromine atom and other groups represent a hydrogen atom areparticularly preferable.

In the formula, R²¹ to R²⁸ each independently represent a hydrogen atom,halogen atom, alkyl group, alkenyl group, aralkyl group, arylthio group,arylalkenyl group, cyclic alkenyl group alkoxy group, aryloxy group,alkyloxycarbonyl group, aralkyloxycarbonyl group, aryloxycarbonyl group,or aryl group. At least one of R²¹ to R²⁸ represents a bromine atom.

Specific examples of, R 21 to R²⁸ are the same as the concrete examplesof the substituent on the ligand Ar′ of a complex of the formula (9)describe above.

The method of producing a complex of the present invention will bedescribed using a method of producing a complex of the general formula(9).

The complex of the general formula (9) can be produced by reacting acomplex of the general formula (11):M′-(L′)s  (11)(L′ has the same meaning as for L′ in the formula (9). s represents aninteger of 0 to 3) with a compound of the general formula (12):Ar′ H  (12)(Ar′ has the same meaning as for Ar′ in the formula (9). Ar′H means thata hydrogen atom is added to a carbon atom bonded to M′ in Ar′.).

As L′, ligands providing a smooth interchange reaction are preferable,such as carboxylate, diketonate group, amide group, imide group,carbonyl ligand, arylene ligand, alkene ligand, alkyne ligand, imineligand, nitrile ligand, ether ligand, sulfone ligand, sulfoxide ligand,sulfide ligand and the like, since they are bonded to a center metalrelatively weakly.

As the above-mentioned Ar′H, commercially available reagents may beused, alternatively, Ar′H may be produced by a known method.

In the production method of the present invention, the ratio of theamount of the complex (11) to the amount of the ligand (12) is aboutfrom 1/0.5 to 1/10 (=complex/ligand) by mol, though it varies dependingon the intended complex prepared.

The reaction is usually conducted in a solvent. As the solvent, forexample, ether-based solvents such as diethyl ether, tetrahydrofuran,tertiary butyl methyl ether, dioxane, and the like; hydrocarbon-basedsolvents such as hexane, cyclohexane, toluene, xylene and the like;ester-based solvents such as ethyl acetate, methyl propionate and thelike, halogen-based solvents such as dichloromethane, chloroform,1,2-dichloroethane and the like, ketone-based solvents such as acetone,methyl isobutyl ketone, diethyl ketone and the like, and alcohol-basedsolvents such as ethanol, butanol, ethylene glycol, glycerin and thelike, are used. The used amount of the solvent is not particularlyrestricted, and usually, from 10 to 500-fold by weight based on thetotal amount of complexes and ligands which are raw materials.

The reaction temperature is not particularly restricted, and usuallyfrom about 50 to 350° C. The reaction time is not particularlyrestricted, and usually from about 30 minutes to 30 hours.

In the synthesis operation, a solvent is poured into a flask, and theatmosphere in the flask was deaerated with an inert gas, for example, anitrogen gas or argon gas, according to bubbling and the like, whilestirring the solvent, then, a complex (11) and a ligand (12) are added.The reaction solution is heated to a temperature at which ligandexchange occurs, while stirring under an inner gas atmosphere, and themixture is heat-insulated and stirring. The completion of the reactioncan be determined by stop of decrease in the raw materials by TLCmonitor and high performance liquid chromatography, or disappearance ofone of the raw materials.

Removal of the intended substance from the reaction mixture andpurification thereof differ depending on the complex, and usuallycomplex purification means are used.

For example, a 1 N aqueous hydrochloric acid solution which is a poorsolvent for a complex is added to cause precipitation of the complex,and this is removed by filtration and this solid is dissolved in anorganic solvent such as dichloromethane, chloroform and the like. Thissolution is filtrated to remove insoluble substances, and concentratedagain, and subjected to purification by silica gel column chromatography(dichloromethane elution), and intended fraction solutions arecollected, and to this is added, for example, a suitable amount ofmethanol (poor solvent), and the mixture is concentrated to precipitatethe intended complex which if filtrated and dried to obtain a complex.The method of producing a complex (9) or (10) is not restricted to theabove-mentioned method.

A polymeric light emitting substance can be produced by using thecomplex of the present invention as a monomer.

Next, the polymer LED of the present invention will be illustrated. Thepolymer LED of the present invention is a polymer LED comprising atleast a light emitting layer between a pair of electrodes composed of ananode and a cathode at least one of which is transparent orsemi-transparent wherein the light emitting layer contains a polymericlight emitting substance of the present invention.

As the polymer LED of the present invention, there are listed polymerLEDs having an electron transporting layer disposed between a cathodeand a light emitting layer, polymer LEDs having a hole transportinglayer disposed between an anode and a light emitting layer, polymer LEDshaving an electron transporting layer disposed between a cathode and alight emitting layer and having a hole transporting layer disposedbetween an anode and a light emitting layer.

There are listed polymer LEDs having an electron conductive polymerlayer disposed between at least either one of the electrodes and a lightemitting layer in adjacent with the electrode; and LEDs having a bufferlayer having an average thickness of 2 nm or less, disposed between atleast either one of the electrodes and a light emitting layer inadjacent with the electrode.

For example, the following structures a) to d) are specificallyexemplified.

a) anode/light emitting layer/cathode

b) anode/hole transporting layer/light emitting layer/cathode

c) anode/light emitting layer/electron transporting layer/cathode

d) anode/hole transporting layer/light emitting layer/electrontransporting layer/cathode

(wherein, “/” indicates adjacent lamination of layers. Hereinafter, thesame.)

Herein, the light emitting layer is a layer having function to emit alight, the hole transporting layer is a layer having function totransport a hole, and the electron transporting layer is a layer havingfunction to transport an electron. Herein, the electron transportinglayer and the hole transporting layer are generically called a chargetransporting layer.

The light emitting layer, hole transporting layer and electrontransporting layer may also each independently used in two or morelayers.

Of charge transporting layers disposed adjacent to an electrode, thathaving function to improve charge injecting efficiency from theelectrode and having effect to decrease driving voltage of an device areparticularly called sometimes a charge injecting layer (hole injectinglayer, electron injecting layer) in general.

For enhancing adherence with an electrode and improving charge injectionfrom an electrode, the above-described charge injecting layer orinsulation layer having a thickness of 2 nm or less may also be providedadjacent to an electrode, and further, for enhancing adherence of theinterface, preventing mixing and the like, a thin buffer layer may alsobe inserted into the interface of a charge transporting layer and lightemitting layer.

The order and number of layers laminated and the thickness of each layercan be appropriately applied while considering light emitting efficiencyand life of the device.

In the present invention, as the polymer LED having a charge injectinglayer (electron injecting layer, hole injecting layer) provided, thereare listed a polymer LED having a charge injecting layer providedadjacent to a cathode and a polymer LED having a charge injecting layerprovided adjacent to an anode.

For example, the following structures e) to p) are specificallyexemplified.

e) anode/charge injecting layer/light emitting layer/cathode

f) anode/light emitting layer/charge injecting layer/cathode

g) anode/charge injecting layer/light emitting layer/charge injectinglayer/cathode

h) anode/charge injecting layer/hole transporting layer/light emittinglayer/cathode

i) anode/hole transporting layer/light emitting layer/charge injectinglayer/cathode

j) anode/charge injecting layer/hole transporting layer/light emittinglayer/charge injecting layer/cathode

k) anode/charge injecting layer/light emitting layer/electrontransporting layer/cathode

l) anode/light emitting layer/electron transporting layer/chargeinjecting layer/cathode

m) anode/charge injecting layer/light emitting layer/electrontransporting layer/charge injecting layer/cathode

n) anode/charge injecting layer/hole transporting layer/light emittinglayer/electron transporting layer/cathode

o) anode/hole transporting layer/light emitting layer/electrontransporting layer/charge injecting layer/cathode

p) anode/charge injecting layer/hole transporting layer/light emittinglayer/electron transporting layer/charge injecting layer/cathode

As the specific examples of the charge injecting layer, there areexemplified layers containing an conducting polymer, layers which aredisposed between an anode and a hole transporting layer and contain amaterial having an ionization potential between the ionization potentialof an anode material and the ionization potential of a hole transportingmaterial contained in the hole transporting layer, layers which aredisposed between a cathode and an electron transporting layer andcontain a material having an electron affinity between the electronaffinity of a cathode material and the electron affinity of an electrontransporting material contained in the electron transporting layer, andthe like.

When the above-described charge injecting layer is a layer containing anconducting polymer, the electric conductivity of the conducting polymeris preferably 10⁻⁵ S/cm or more and 10³ S/cm or less, and for decreasingthe leak current between light emitting pixels, more preferably 10⁻⁵S/cm or more and 10² S/cm or less, further preferably 10⁻⁵ S/cm or moreand 10¹ S/cm or less.

Usually, to provide an electric conductivity of the conducting polymerof 10⁻⁵ S/cm or more and 10³ S/cm or less, a suitable amount of ions aredoped into the conducting polymer.

Regarding the kind of an ion doped, an anion is used in a hole injectinglayer and a cation is used in an electron injecting layer. As examplesof the anion, a polystyrene sulfonate ion, alkylbenzene sulfonate ion,camphor sulfonate ion and the like are exemplified, and as examples ofthe cation, a lithium ion, sodium ion, potassium ion, tetrabutylammonium ion and the like are exemplified.

The thickness of the charge injecting layer is for example, from 1 nm to100 nm, preferably from 2 nm to 50 nm.

Materials used in the charge injecting layer may properly be selected inview of relation with the materials of electrode and adjacent layers,and there are exemplified conducting polymers such as polyaniline andderivatives thereof, polythiophene and derivatives thereof, polypyrroleand derivatives thereof, poly(phenylene vinylene) and derivativesthereof, poly(thienylene vinylene) and derivatives thereof,polyquinoline and derivatives thereof, polyquinoxaline and derivativesthereof, polymers containing aromatic amine structures in the main chainor the side chain, and the like, and metal phthalocyanine (copperphthalocyanine and the like), carbon and the like.

The insulation layer having a thickness of 2 nm or less has function tomake charge injection easy. As the material of the above-describedinsulation layer, metal fluoride, metal oxide, organic insulationmaterials and the like are listed. As the polymer LED having aninsulation layer having a thickness of 2 nm or less, there are listedpolymer LEDs having an insulation layer having a thickness of 2 nm orless provided adjacent to a cathode, and polymer LEDs having aninsulation layer having a thickness of 2 nm or less provided adjacent toan anode.

Specifically, there are listed the following structures q) to ab) forexample.

q) anode/insulation layer having a thickness of 2 nm or less/lightemitting layer/cathode

r) anode/light emitting layer/insulation layer having a thickness of 2nm or less/cathode

s) anode/insulation layer having a thickness of 2 nm or less/lightemitting layer/insulation layer having a thickness of 2 nm orless/cathode

t) anode/insulation layer having a thickness of 2 nm or less/holetransporting layer/light emitting layer/cathode

u) anode/hole transporting layer/light emitting layer/insulation layerhaving a thickness of 2 nm or less/cathode

v) anode/insulation layer having a thickness of 2 nm or less/holetransporting layer/light emitting layer/insulation layer having athickness of 2 nm or less/cathode

w) anode/insulation layer having a thickness of 2 nm or less/lightemitting layer/electron transporting layer/cathode

x) anode/light emitting layer/electron transporting layer/insulationlayer having a thickness of 2 nm or less/cathode

y) anode/insulation layer having a thickness of 2 nm or less/lightemitting layer/electron transporting layer/insulation layer having athickness of 2 nm or less/cathode

z) anode/insulation layer having a thickness of 2 nm or less/holetransporting layer/light emitting layer/electron transportinglayer/cathode

aa) anode/hole transporting layer/light emitting layer/electrontransporting layer/insulation layer having a thickness of 2 nm orless/cathode

ab) anode/insulation layer having a thickness of 2 nm or less/holetransporting layer/light emitting layer/electron transportinglayer/insulation layer having a thickness of 2 nm or less/cathode

In producing a polymer LED, when a film is formed from a solution byusing such polymeric light emitting substance soluble in an organicsolvent, only required is removal of the solvent by drying after coatingof this solution, and even in the case of mixing of a chargetransporting material and a light emitting material, the same method canbe applied, causing an extreme advantage in production. As the filmforming method from a solution, there can be used coating methods suchas a spin coating method, casting method, micro gravure coating method,gravure coating method, bar coating method, roll coating method, wirebar coating method, dip coating method, spray coating method, screenprinting method, flexo printing method, offset printing method, inkjetprinting method and the like.

Regarding the thickness of the light emitting layer, the optimum valuediffers depending on material used, and may properly be selected so thatthe driving voltage and the light emitting efficiency become optimumvalues, and for example, it is from 1 nm to 1 μm, preferably from 2 nmto 500 nm, further preferably from 5 nm to 200 nm.

In the polymer LED of the present invention, a light emitting materialother than the above-mentioned polymeric light emitting substances maybe mixed in a light emitting layer. Further, in the polymer LEDaccording to the instant application, a light emitting layer containinga light emitting material other than the above-mentioned polymeric lightemitting substance may be laminated with a light emitting layercontaining the above-mentioned polymeric light emitting substance.

As the light emitting material, known materials can be used. In acompound having lower molecular weight, there can be used, for example,naphthalene derivatives, anthracene or derivatives thereof, perylene orderivatives thereof dyes such as polymethine dyes, xanthene dyes,coumarine dyes, cyanine dyes; metal complexes of 8-hydroxyquinoline orderivatives thereof, aromatic amine, tetraphenylcyclopentane orderivatives thereof, or tetraphenylbutadiene or derivatives thereof, andthe like.

Specifically, there can be used known compounds such as those describedin JP-A Nos. 57-51781, 59-195393 and the like, for example.

When the polymer LED of the present invention has a hole transportinglayer, as the hole transporting materials used, there are exemplifiedpolyvinylcarbazole or derivatives thereof, polysilane or derivativesthereof, polysiloxane derivatives having an aromatic amine in the sidechain or the main chain, pyrazoline derivatives, arylamine derivatives,stilbene derivatives, triphenyldiamine derivatives, polyaniline orderivatives thereof, polythiophene or derivatives thereof, polypyrroleor derivatives thereof, poly(p-phenylenevinylene) or derivativesthereof, poly(2,5-thienylenevinylene) or derivatives thereof, or thelike.

Specific examples of the hole transporting material include thosedescribed in JP-A Nos. 63-70257, 63-175860, 2-135359, 2-135361,2-209988, 3-37992 and 3-152184.

Among them, as the hole transporting materials. used in the holetransporting layer, preferable are polymer hole transporting materialssuch as polyvinylcarbazole or derivatives thereof, polysilane orderivatives thereof, polysiloxane derivatives having an aromatic aminecompound group in the side chain or the main chain, polyaniline orderivatives thereof, polythiophene or derivatives thereof,poly(p-phenylenevinylene) or derivatives thereof,poly(2,5-thienylenevinylene) or derivatives thereof, or the like, andfurther preferable are polyvinylcarbazole or derivatives thereof,polysilane or derivatives thereof and polysiloxane derivatives having anaromatic amine compound group in the side chain or the main chain. Inthe case of a hole transporting material having lower molecular weight,it is preferably dispersed in a polymer binder for use.

Polyvinylcarbazole or derivatives thereof are obtained, for example, bycation polymerization or radical polymerization from a vinyl monomer.

As the polysilane or derivatives thereof, there are exemplifiedcompounds described in Chem. Rev., 89, 1359 (1989) and GB 2300196published specification, and the like. For synthesis, methods describedin them can be used, and a Kipping method can be suitably usedparticularly.

As the polysiloxane or derivatives thereof, those having the structureof the above-described hole transporting material having lower molecularweight in the side chain or main chain, since the siloxane skeletonstructure has poor hole transporting property. Particularly, there areexemplified those having an aromatic amine having hole transportingproperty in the side chain or main chain.

The method for forming a hole transporting layer is not restricted, andin the case of a hole transporting layer having lower molecular weight,a method in which the layer is formed from a mixed solution with apolymer binder is exemplified. In the case of a polymer holetransporting material, a method in which the layer is formed from asolution is exemplified.

The solvent used for the film forming from a solution is notparticularly restricted providing it can dissolve a hole transportingmaterial. As the solvent, there are exemplified chlorine solvents suchas chloroform, methylene chloride, dichloroethane and the like, ethersolvents such as tetrahydrofuran and the like, aromatic hydrocarbonsolvents such as toluene, xylene and the like, ketone solvents such asacetone, methyl ethyl ketone and the like, and ester solvents such asethyl acetate, butyl acetate, ethylcellosolve acetate and the like.

As the film forming method from a solution, there can be used coatingmethods such as a spin coating method, casting method, micro gravurecoating method, gravure coating method, bar coating method, roll coatingmethod, wire bar coating method, dip coating method, spray coatingmethod, screen printing method, flexo printing method, offset printingmethod, inkjet printing method and the like, from a solution.

The polymer binder mixed is preferably that does not disturb chargetransport extremely, and that does not have strong absorption of avisible light is suitably used. As such polymer binder, polycarbonate,polyacrylate, poly(methyl acrylate), poly(methyl methacrylate),polystyrene, poly(vinyl chloride), polysiloxane and the like areexemplified.

Regarding the thickness of the hole transporting layer, the optimumvalue differs depending on material used, and may properly be selectedso that the driving voltage and the light emitting efficiency becomeoptimum values, and at least a thickness at which no pin hole isproduced is necessary, and too large thickness is not preferable sincethe driving voltage of the device increases. Therefore, the thickness ofthe hole transporting layer is, for example, from 1 nm to 1 μm,preferably from 2 nm to 500 nm, further preferably from 5 nm to 200 nm.

When the polymer LED of the present invention has an electrontransporting layer, known compounds are used as the electrontransporting materials, and there are exemplified oxadiazolederivatives, anthraquinonedimethane or derivatives thereof, benzoquinoneor derivatives thereof, naphthoquinone or derivatives thereof,anthraquinone or derivatives thereof, tetracyanoanthraquinodimethane orderivatives thereof, fluorenone derivatives, diphenyldicyanoethylene orderivatives thereof, diphenoquinone derivatives, or metal complexes of8-hydroxyquinoline or derivatives thereof, polyquinoline and derivativesthereof, polyquinoxaline and derivatives thereof, polyfluorene orderivatives thereof, and the like.

Specifically, there are exemplified those described in JP-A Nos.63-70257, 63-175860, 2-135359, 2-135361, 2-209988, 3-37992 and 3-152184.

Among them, oxadiazole derivatives, benzoquinone or derivatives thereof,anthraquinone or derivatives thereof, or metal complexes of8-hydroxyquinoline or derivatives thereof, polyquinoline and derivativesthereof, polyquinoxaline and derivatives thereof, polyfluorene orderivatives thereof are preferable, and2-(4-biphenyl)-5-(4-t-butylphenyl)-1,3,4-oxadiazole, benzoquinone,anthraquinone, tris(8-quinolinol)aluminum and polyquinoline are furtherpreferable.

The method for forming the electron transporting layer is notparticularly restricted, and in the case of an electron transportingmaterial having lower molecular weight, a vapor deposition method from apowder, or a method of film-forming from a solution or melted state isexemplified, and in the case of a polymer electron transportingmaterial, a method of film-forming from a solution or melted state isexemplified, respectively. When film-forming is conducted from asolution or melted state, a polymer binder may be used together.

The solvent used in the film-forming from a solution is not particularlyrestricted provided it can dissolve electron transporting materialsand/or polymer binders. As the solvent, there are exemplified chlorinesolvents such as chloroform, methylene chloride, dichloroethane and thelike, ether solvents such as tetrahydrofuran and the like, aromatichydrocarbon solvents such as toluene, xylene and the like, ketonesolvents such as acetone, methyl ethyl ketone and the like, and estersolvents such as ethyl acetate, butyl acetate, ethylcellosolve acetateand the like.

As the film-forming method from a solution or melted state, there can beused coating methods such as a spin coating method, casting method,micro gravure coating method, gravure coating method, bar coatingmethod, roll coating method, wire bar coating method, dip coatingmethod, spray coating method, screen printing method, flexo printingmethod, offset printing method, inkjet printing method and the like.

The polymer binder to be mixed is preferably that which does notextremely disturb a charge transport property, and that does not havestrong absorption of a visible light is suitably used. As such polymerbinder, poly(N-vinylcarbazole), polyaniline or derivatives thereof,polythiophene or derivatives thereof, poly(p-phenylene vinylene) orderivatives thereof, poly(2,5-thienylenevinylene) or derivativesthereof, polycarbonate, polyacrylate, poly(methyl acrylate), poly(methylmethacrylate),polystyrene, poly(vinyl chloride), polysiloxane and thelike are exemplified.

Regarding the thickness of the electron transporting layer, the optimumvalue differs depending on material used, and may properly be selectedso that the driving voltage and the light emitting efficiency becomeoptimum values, and at least a thickness at which no pin hole isproduced is necessary, and too large thickness is not preferable sincethe driving voltage of the device increases. Therefore, the thickness ofthe electron transporting layer is, for example, from 1 nm to 1 μm,preferably from 2 nm to 500 nm, further preferably from 5 nm to 200 nm.

The substrate forming the polymer LED of the present invention maypreferably be that does not change in forming an electrode and layers oforganic materials, and there are exemplified glass, plastics, polymerfilm, silicon substrates and the like. In the case of a opaquesubstrate, it is preferable that the opposite electrode is transparentor semitransparent.

In the present invention, it is preferable that an anode is transparentor semitransparent, and as the material of this anode, electronconductive metal oxide films, semitransparent metal thin films and thelike are used. Specifically, there are used indium oxide, zinc oxide,tin oxide, and films (NESA and the like) fabricated by using an electronconductive glass composed of indium.tin.oxide (ITO), indium.zinc.oxideand the like, which are metal oxide complexes, and gold, platinum,silver, copper and the like are used, and among them, ITO,indium.zinc.oxide, tin oxide are preferable. As the fabricating method,a vacuum vapor deposition method, sputtering method, ion plating method,plating method and the like are used. As the anode, there may also beused organic transparent conducting films such as polyaniline orderivatives thereof, polythiophene or derivatives thereof and the like.

The thickness of the anode can be appropriately selected whileconsidering transmission of a light and electric conductivity, and forexample, from 10 nm to 10 μm, preferably from 20 nm to 1 μm, furtherpreferably from 50 nm to 500 nm.

Further, for easy charge injection, there may be provided on the anode alayer comprising a phthalocyanine derivative conducting polymers, carbonand the like, or a layer having an average film thickness of 2 nm orless comprising a metal oxide, metal fluoride, organic insulatingmaterial and the like.

As the material of a cathode used in the polymer LED of the presentinvention, that having lower work function is preferable. For example,there are used metals such as lithium, sodium, potassium, rubidium,cesium, beryllium, magnesium, calcium, strontium, barium, aluminum,scandium, vanadium, zinc, yttrium, indium, cerium, samarium, europium,terbium, ytterbium and the like, or alloys comprising two of more ofthem, or alloys comprising one or more of them with one or more of gold,silver, platinum, copper, manganese, titanium, cobalt, nickel, tungstenand tin, graphite or graphite intercalation compounds and the like.Examples of alloys include a magnesium-silver alloy, magnesium-indiumalloy, magnesium-aluminum alloy, indium-silver alloy, lithium-aluminumalloy, lithium-magnesium alloy, lithium-indium alloy, calcium-aluminumalloy and the like. The cathode may be formed into a laminated structureof two or more layers.

The film thickness of a cathode can be appropriately selected in view ofelectric conductivity and durability, and for example, it is from 10 nmto 10 μm, preferably from 20 nm to 1 μm, further preferably from 50 nmto 500 nm.

As the method for fabricating a cathode, there are used a vacuum vapordeposition method, sputtering method, lamination method in which a metalthin film is adhered under heat and pressure, and the like. Further,there may also be provided, between a cathode and an organic layer, alayer comprising an conducting polymer, or a layer having an averagefilm thickness of 2 nm or less comprising a metal oxide, metal fluoride,organic insulation material and the like, and after fabrication of thecathode, a protective layer may also be provided which protects thepolymer LED. For stable use of the polymer LED for a long period oftime, it is preferable to provide a protective layer and/or protectivecover for protection of the device in order to prevent it from outsidedamage.

As the protective layer, there can be used a polymer compound, metaloxide, metal fluoride, metal borate and the like. As the protectivecover, there can be used a glass plate, a plastic plate the surface ofwhich has been subjected to lower-water-permeation treatment, and thelike, and there is suitably used a method in which the cover is pastedwith an device substrate by a thermosetting resin or light-curing resinfor sealing. If space is maintained using a spacer, it is easy toprevent an device from being injured. If an inner gas such as nitrogenand argon is sealed in this space, it is possible to prevent oxidationof a cathode, and further, by placing a desiccant such as barium oxideand the like in the above-described space, it is easy to suppress thedamage of an device by moisture adhered in the production process. Amongthem, any one means or more are preferably adopted.

For obtaining light emission in plane form using the polymer LED of thepresent invention, an anode and a cathode in the plane form may properlybe placed so that they are laminated each other. Further, for obtaininglight emission in pattern form, there are a method in which a mask witha window in pattern form is placed on the above-described plane lightemitting device, a method in which an organic layer in non-lightemission part is formed to obtain extremely large thickness providingsubstantial non-light emission, and a method in which any one of ananode or a cathode, or both of them are formed in the pattern. Byforming a pattern by any of these methods and by placing some electrodesso that independent on/off is possible, there is obtained a displaydevice of segment type which can display digits, letters, simple marksand the like. Further, for forming a dot matrix device, it may beadvantageous that anodes and cathodes are made in the form of stripesand placed so that they cross at right angles. By a method in which aplurality of kinds of polymeric light emitting substances emittingdifferent colors of lights are placed separately or a method in which acolor filter or luminescence converting filter is used, area colordisplays and multi color displays are obtained. A dot matrix display canbe driven by passive driving, or by active driving combined with TFT andthe like. These display devices can be used as a display of a computer,television, portable terminal, portable telephone, car navigation, viewfinder of a video camera, and the like.

Further, the above-described light emitting device in plane form is athin self-light-emitting one, and can be suitably used as a flat lightsource for back-light of a liquid crystal display, or as a flat lightsource for illumination. Further, if a flexible plate is used, it canalso be used as a curved light source or a display.

EXAMPLES

Examples will be shown below to explain the present invention further indetail, but these examples do not limit the scope of the invention.

Here, the number-average molecular weight was measured inpolystyrene-reduced number-average molecular weight by a gel permeationchromatography (GPC) using chloroform as a solvent.

Example 1

<Production of 2-(bromophenyl)pyridine>

3 g (19.3 mmol) of 2-phenylpyridine and 40 mg (0.716 mmol) of an ironpowder were mixed and stirred. 4.0 g (25 mmol) of bromine was droppedpaying attention to heat generation while stirring and cooling themixture to 0° C., and the mixture was heated up to 90° C. and stirredfor 10 hours. After completion of the reaction, this reaction mixturewas dissolved in chloroform, and washed with a 5% aqueous sodiumthiosulfate solution. The chloroform solution was dried over sodiumsulfate, then, concentrated, and the residue was purified by silica gelcolumn chromatography, to obtain the intended 2-(bromophenyl)pyridine.

The yield amount was 1.6 g (6.83 mmol) and the yield was 35.4%. M+ wasmeasured to be 234.0 by LC-MS.

<Production of tris(2-bromophenyl)pyridine)iridum (III)>

50 mg (0.1021 mmol) of a trisacetylacetonateiridum (III) complex and95.6 mg (0.4084 mmol) of 2-bromophenylpyridine and 20 ml of glycol werepoured into a 50 ml flask in the form of eggplant and refluxed for 10hours. To this reaction solution was added 100 ml of a 1 N hydrochloricacid aqueous solution, and the mixture was stirred for 30 minutes, Theprecipitated solid was removed by filtration, and dissolved again in asmall amount of methylene chloride, to give a solution. This solutionwas filtrated by silica gel column chromatography, to remove excessmetal decomposed substances derived from the iridium complex.Thereafter, the resulted solution was concentrated to the intermediateextent, and methanol was added to this and the precipitated yellow solidwas recovered by filtration.

10.12 mg (0.0113 mmol) of the intended substance,tris(2-(bromophenyl)pyridine)iridium(III) was obtained. The yield was11.1%. M+ was measured to be 893 by FD-MS.

Example 2

<Production ofbis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)>

0.642 g (1.31 mmol) of a trisacetylacetonateiridium (III) complex, 0.41g (1.75 mmol) of 2-(bromophenyl)pyridine, 0.54 g (3.5 mmol) of2-(phenyl)pyridine and 50 ml of glycol were poured into a 100 ml flaskin the form of eggplant and refluxed for 10 hours. To this reactionsolution was added 100 ml of a 1 N hydrochloric acid aqueous solution,and the mixture was stirred for 30 minutes, The precipitated solid wasremoved by filtration, and dissolved again in a small amount ofmethylene chloride, to give a solution. This solution was filtrated bysilica gel column chromatography, to remove excess metal decomposedsubstances derived from the iridium complex. Thereafter, the resultedsolution was concentrated to the intermediate extent, and methanol wasadded to this and the precipitated yellow solid was recovered byfiltration. 0.13 g (0.177 mmol) of a mixture consisting ofbis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridum (III) as themain component was obtained. The yield was about

13.5%. M+ was measured to be 733 by FD-MS. This mixture is a mixture oftris(2-(bromophenyl)pyridine)iridium (III) complex (complex 4),mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)complex (complex 3),bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III)complex (complex 2), and tris(2-(phenyl)pyridine)iridium (III) complex(complex 1). The ratios of them measured by FD-MS are as shown in Table1.

TABLE 1 FD-MS of complex Peak Composition ratio (%) Remarks Complex 1 3112.2 Discharged out of the system without reaction Complex 2 86 33.7Reacted to the end of a molecule Complex 3 100 39.2 Complex 4 38 14.9

Example 3

<Synthesis of Polymeric Light Emitting Substance 1>

0.403 g (0.735 mmol) of 9,9-dioctyl-2,7-dibromofluorene, 0.321 g (0.735mmol) of N-octyl-3,6-dibromocarbazole, 0.022 g ofbis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium (III) (0.03mmol: this mixtures is a mixture of atris(2-(bromophenyl)pyridine)iridium (III) complex,mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)complex, bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium(III) complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and incharging, bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium(III) having a molecular weight of 733 was used) and 0.55 g (3.5 mmol)of 2,2′-bipyridyl were charged in a reaction vessel, then, theatmosphere in the reaction vessel was purged with a nitrogen gas. Tothis was added 40 ml of tetrahydrofuran (dehydrated solvent) previouslydegassed by bubbling of an argon gas. Then, to this mixed solution wasadded 0.96 g (3.5 mmol) of bis(1,5-cyclooctadiene)nickel (0), theresulted mixture was stirred for 10 minutes at room temperature, then,they were reacted for 8 hours at 60° C. The reaction was conducted undera nitrogen atmosphere. After the reaction, this solution was cooled,then, poured into a mixed solution of 10 ml of 25% ammonia water/150 mlof methanol/50 ml of ion exchanged water, and they were stirred forabout 30 minutes. Then, the produced precipitate was filtrated andrecovered. This precipitation was dried, then, dissolved in chloroform.This solution was filtrated to remove insoluble substances, then, thissolution was poured into methanol, to cause re-precipitation, and theproduced precipitation was recovered. This precipitation was dried underreduced pressure, to obtain 0.11 g of a polymer. This polymer is calledpolymeric light emitting substance 1.

The polymeric light emitting substance 1 had a polystyrene reducedweight-average molecular weight of 4.4×10⁵ and a polystyrene reducednumber-average molecular weight of 1.9×10⁵.

The polymeric light emitting substance 1 is a copolymer containing9,9-dioctyl-2,7-fluorene, N-octyl-3,6-carbazole and tris(2-(phenyl)pyridine)iridium (III) complex as repeating units.

Example 4

<Synthesis of Polymeric Light Emitting Substance 2>

0.403 g (0.735 mmol) of 9,9-dioctyl-2,7-dibromofluorene, 0.496 g (0.735mmol) of N,N′-diphenyl-N,N′-bis(3-methyl-4-bromophenyl)benzidine, 0.022g of bis (2-(phenyl)pyridine)mono (2-(bromophenyl)pyridine)iridium (III)(0.03 mmol: this mixtures is a mixture of a tris(2-(bromophenyl)pyridine) iridium (III) complex, mono(2-(phenyl)pyridine)bis (2-(bromophenyl)pyridine)iridium (III) complex,bis (2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine) iridium (III)complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and incharging, bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium(III) having a molecular weight of 733 was used) and 0.55 g (3.5 mmol)of 2,2′-bipyridyl were charged in a reaction vessel, then, theatmosphere in the reaction vessel was purged with a nitrogen gas. Tothis was added 40 ml of tetrahydrofuran (dehydrated solvent) previouslydegassed by bubbling of an argon gas. Then, to this mixed solution wasadded 0.96 g (3.5 mmol) of bis(1,5-cyclooctadiene)nickel (0), theresulted mixture was stirred for 10 minutes at room temperature, then,they were reacted for 8 hours at 60° C. The reaction was conducted undera nitrogen atmosphere. After the reaction, this solution was cooled,then, poured into a mixed solution of 10 ml of 25% ammonia water/150 mlof methanol/50 ml of ion exchanged water, and they were stirred forabout 30 minutes. Then, the produced precipitate was filtrated andrecovered. This precipitation was dried, then, dissolved in chloroform.This solution was filtrated to remove insoluble substances, then, thissolution was poured into methanol, to cause re-precipitation, and theproduced precipitation was recovered. This precipitation was dried underreduced pressure, to obtain 0.35 g of a polymer. This polymer is calledpolymeric light emitting substance 2.

The polymeric light emitting substance 2 had a polystyrene reducedweight-average molecular weight of 3.6×10⁵ and a polystyrene reducednumber-average molecular weight of 1.8×10⁴.

The polymeric light emitting substance 2 is a copolymer containing9,9-dioctyl-2,7-fluorene,N,N′-diphenyl-N,N′-bis(3-methylphenyl)benzidine andtris(2-(phenyl)pyridine)iridium (III) complex as repeating units.

Example 5

<Synthesis of Polymeric Light Emitting Substance 3>

0.806 g (1.47 mmol) of 9,9-dioctyl-2,7-dibromofluorene, 0.022 g ofbis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridiu m (III) (0.03mmol: this mixtures is a mixture of atris(2-(bromophenyl)pyridine)iridium (III) complex,mono(2-(phenyl)pyridine)bis(2-(bromophenyl)pyridine)iridium (III)complex, bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium(III) complex, and tris(2-(phenyl)pyridine)iridium (III) complex, and incharging, bis(2-(phenyl)pyridine)mono(2-(bromophenyl)pyridine)iridium(III) having a molecular weight of 733 was used) and 0.55 g (3.5 mmol)of 2,2′-bipyridyl were charged in a reaction vessel, then, theatmosphere in the reaction vessel was purged with a nitrogen gas. Tothis was added 40 ml of tetrahydrofuran (dehydrated solvent) previouslydegassed by bubbling of an argon gas. Then, to this mixed solution wasadded 0.96 g (3.5 mmol) of bis (1,5-cyclooctadiene)nickel (0), theresulted mixture was stirred for 10 minutes at room temperature, then,they were reacted for 8 hours at 60° C. The reaction was conducted undera nitrogen atmosphere. After the reaction, this solution was cooled,then, poured into a mixed solution of 10 ml of 25% ammonia water/150 mlof methanol/50 ml of ion exchanged water, and they were stirred forabout 30 minutes. Then, the produced precipitate was filtrated andrecovered. This precipitation was dried, then, dissolved in chloroform.This solution was filtrated to remove insoluble substances, then, thissolution was poured into methanol, to cause re-precipitation, and theproduced precipitation was recovered. This precipitation was dried underreduced pressure, to obtain 0.11 g of a polymer. This polymer is calledpolymeric light emitting substance 3.

The polymeric light emitting substance 3 had a polystyrene reducedweight-average molecular weight of 7.6×10⁴ and a polystyrene reducednumber-average molecular weight of 1.2×10⁴.

The polymeric light emitting substance 3 is a copolymer containing9,9-dioctyl-2,7-fluorene, and tris(2-(phenyl)pyridine)iridium (III)complex as repeating units.

Example 6

<Polymer LED>

On a glass substrate carrying there on an ITO film adhered at athickness of 150 nm by a sputtering method, a film was formed at athickness of 50 nm by spin coat using a solution ofpoly(ethylenedioxythiophene)/polstyrenesulfonic acid (Baytron,manufactured by Bayer), and dried at 120° C. for 5 minutes on a hotplate. Then, a film was formed at a thickness of about 70 mm by spincoat using a 0.5 wt % solution of the polymeric light emitting substance1 in chloroform. Further, this was dried at 80° C. under reducedpressure for 1 hour, then, lithium fluoride was deposited at a thicknessof 0.4 nm as a cathode buffer layer, calcium was deposited at athickness of 25 nm, then, aluminum was deposited at a thickness of 40nm, as a cathode, to produce a polymer LED. The degree of vacuum indeposition was always 1 to 8×10⁻⁶ Torr. By applying voltage on theresulted device, EL light emission from the polymeric light emittingsubstance 1 was obtained. The intensity of EL emission was approximatelyin proportion to current density.

Example 6

<Calculation Examples of Intersystem Crossing>

The structure of the minimum triplet excited state of atris(2-phenylpyridine)iridium complex was analyzed by a B3LYP methodusing the LANL2 MB base function. Regarding the structure, thedifference between energy between the minimum singlet excited state andthe minimum triplet excited state was measured by a TDDFT method atB3LYP/LANL2 MB level, to find it was 0.87 eV. For the calculation,Caussian 98 program was used.

The polymeric light emitting substance of the present invention has acomplex emitting triplet luminescence structure in the molecule, and canform a light emitting layer by industrially simple application methodssuch as a spin coat method, inkjet method, printing method and the like.Further, the polymeric light emitting substance of the present inventioncontains a complex emitting triplet luminescence, and can manifest highlight emitting efficiency. Therefore, the polymeric light emittingsubstance of the present invention can be used suitably as a lightemitting material of a polymer LED, and the like. According to theproduction method of the present invention, this polymeric lightemitting substance can be produced easily. The polymer LED of thepresent invention can be preferably used in apparatuses such as a backlight of a liquid crystal display, light sources in the form of curve orflat plate for illumination, display elements of segment type, flatpanel displays of dot matrix, and the like.

1. A polymeric light emitting substance having a polystyrene reducednumber-average molecular weight of from 10³ to 10⁸ wherein said lightemitting substance has a metal complex structure showing light emissionfrom the triplet excited state at least at one of the ends of the mainchain, wherein the main chain comprises a conjugated polymer, and themetal complex structure is represented by the below formula (6):

wherein M represents a metal atom having an atomic number of 50 or moreand showing a possibility of the intersystem crossing between thesinglet state and the triplet state in this complex by a spin-orbitalmutual action; Ar represents a ligand bonded to M, via one or more of anitrogen atom, an oxygen atom, a carbon atom, a sulfur atom and aphosphorus atom, with bonding to a polymer at an arbitrary bondingposition of the ligand; L represents a hydrogen atom, a hydrocarbongroup having 1 to 10 carbon atoms, a carboxylate group having 1 to 10carbon atoms, a diketonate group having 1 to 10 carbon atoms, a halogenatom, an amide group, an imide group, an alkoxide group, analkylmercapto group, a carbonyl ligand, an arylene ligand, an alkeneligand, an alkyne ligand, an amine ligand, an imine ligand, a nitrileligand, an isonitrile ligand, a phosphine ligand, a phosphine oxideligand, a phosphite ligand, an ether ligand, a sulfone ligand, asulfoxide ligand, a sulfide ligand or a heterocyclic compound group; mrepresents an integer of 1 to 5; and o represents an integer of 0 to 5,wherein M is a rhenium atom, osmium atom, iridium atom, platinum atom orgold atom, wherein the polymeric light emitting substance comprises oneor more repeating units selected from the group consisting of thegeneral formulas (1), (2) and (5) and one or more repeating units havinga metal complex structure showing light emission from the tripletexcited state, and the amount of the repeating units having a metalcomplex structure showing light emission from the triplet excited stateis 0.01 mol % or more and 10 mol % or less based on the total amount ofthe repeating units of the general formulas (1), (2) and (5) and therepeating units having a metal complex structures showing light emissionfrom the triplet excited state,

wherein Ar₁ represents an arylene group or a divalent heterocycliccompound group; R₁ and R₂ each independently represent a hydrogen atom,an alkyl group, an aryl group, a monovalent heterocyclic compound groupor a cyano group; and n represents 0 or 1;

wherein Ar₂ and Ar₃ each independently represents an arylene group, or adivalent heterocyclic compound group; Ar₂ does not cross-link to Ar₃;R₁₁ represents an alkyl group, an aryl group, a mono-valent heterocycliccompound group, or a group represented by the below formula (3) or (4);the symbol t is an integer from 1 to 4;

wherein Ar₄ is an arylene group or a divalent heterocyclic compoundgroup; R₁₂ represents a hydrogen atom, an alkyl group, an aryl group, amono-valent heterocyclic group, or a group represented by the belowformula (4); Z₁ represents —CR₁₃═CR₁₄— or —C≡C—; R₁₃ and R₁₄ eachindependently represents a hydrogen atom, an alkyl group, an aryl group,a mono-valent heterocyclic group, or a cyano group; the symbol u is aninteger from 0 to 2;

wherein Ar₅ and Ar₆ each independently represents an arylene group or adivalent heterocyclic compound group; R₁₅ represents an alkyl group, anaryl group, or a mono-valent heterocyclic group; and the symbol v is aninteger from 1 to 4;

wherein R₁₁ means the same as above; R₁₈ and R₁₉ each independentlyrepresents substituents on aromatic ring of a halogen atom, an alkylgroup, an alkenyl group, an aralkyl group, an arylthio group, anarylalkenyl group, a cyclic alkenyl group, an alkoxy group, an aryloxygroup, an alkyloxy carbonyl group, an aralkyloxy carbonyl group, anaryloxy carbonyl group, an aryl group, or a mono-valent heterocyclicgroup; the symbols a and b each independently represent an integer from0 to 3; and when a or b is 2 or more, R₁₈ and R₁₉ are the same ordifferent mutually, which may be connected to form a ring.
 2. Thepolymeric light emitting substance according to claim 1, wherein saidlight emitting substance has two or more kinds of the metal complexstructure showing light emission from the triplet excited state.
 3. Thepolymeric light emitting substance according to claim 1, wherein atleast one ligand contained in the metal complex structure comprises thesame structure with a repeating unit contained in the main chain.
 4. Thepolymeric light emitting substance according to claim 1, comprising oneor more repeating units of the general formula (1) and one or morerepeating units having a metal complex structure showing light emissionfrom the triplet excited state:

wherein Ar₁ represents an arylene group or a divalent heterocycliccompound group; R₁ and R₂ each independently represents a hydrogen atom,an alkyl group, an aryl group, a monovalent heterocyclic compound groupor a cyano group; and n represents 0 or
 1. 5. The polymeric lightemitting substance according to claim 1, comprising one or morerepeating units of the formula (2),

wherein Ar₂ and Ar₃ each independently represents an arylene group, or adivalent heterocyclic compound group; Ar₂ does not cross-link to Ar₃;R₁₁ represents an alkyl group, an aryl group, a mono-valent heterocycliccompound group, or a group represented by the below formula (3) or (4);the symbol t is an integer from 1 to 4;

wherein Ar₄ is an arylene group or a divalent heterocyclic compoundgroup; R₁₂ represents a hydrogen atom, an alkyl group, an aryl group, amono-valent heterocyclic group, or a group represented by the belowformula (4); Z₁ represents —CR₁₃═CR₁₄— or —C≡C—; R₁₃ and R₁₄ eachindependently represents a hydrogen atom, an alkyl group, an aryl group,a mono-valent heterocyclic group, or a cyano group; the symbol u is aninteger from 0 to 2;

wherein Ar₅ and Ar₆ each independently represents an arylene group or adivalent heterocyclic compound group; R₁₅ represents an alkyl group, anaryl group, or a mono-valent heterocyclic group; and the symbol v is aninteger from 1 to
 4. 6. The polymeric light emitting substance accordingto claim 4, comprising one or more repeating units of the formula (5),

wherein R₁₁ means the same as above; R₁₈ and R₁₉ each independentlyrepresents substituents on aromatic ring of a halogen atom, an alkylgroup, an alkenyl group, an aralkyl group, an arylthio group, anarylalkenyl group, a cyclic alkenyl group, an alkoxy group, an aryloxygroup, an alkyloxy carbonyl group, an aralkyloxy carbonyl group, anaryloxy carbonyl group, an aryl group, or a mono-valent heterocyclicgroup; the symbols a and b each independently represent an integer from0 to 3; and when a or b is 2 or more, R₁₈ and R₁₉ are the same ordifferent mutually, which may be connected to form a ring.
 7. Thepolymeric light emitting substance according to claim 1, wherein M bondsto at least one carbon atom.
 8. The polymeric light emitting substanceaccording to claim 1, wherein Ar represents a bidentate ligand forming a5 membered ring by bonding to M, via a nitrogen atom, an oxygen atom, acarbon atom, a sulfur atom or a phosphor atom.
 9. The polymeric lightemitting substance according to claim 1, wherein Ar represents abidentate ligand represented by the formula (7),

wherein R³ to R¹⁰each independently represents a halogen atom, an alkylgroup, an alkenyl group, an aralkyl group, an arylthio group, anarylalkenyl group, a cyclic alkenyl group, an alkoxy group, an aryloxygroup, an alkyloxy carbonyl group, an aralkyloxy carbonyl group, anaryloxy carbonyl group, or an aryl group; and at least one of R³ to R¹⁰is a bonding group to a polymer chain.
 10. A method for producing apolymeric light emitting substance of claim 4, comprising reacting amonomer of X₁-A-X₂ with X₃—Ar₁—X₄ in the presence of a Ni catalyst,wherein, X₁ and X₂ each independently represent a halogen atom,alkylsulfonyloxy group or arylsulfonyloxy group; -A- represents arepeating unit having a metal complex structure showing light emissionfrom the triplet excited state; X₃ and X₄ each independently represent ahalogen atom, alkylsulfonyloxy group or arylsulfonyloxy group.
 11. Amethod for producing a polymeric light emitting substance of claim 4,comprising reacting a monomer of Y₁-A-Y₂ with a monomer of Z₁—Ar—Z₂ inthe presence of a Pd catalyst, wherein Y₁ and Y₂ each independentlyrepresent a boric acid group or borate group; and Z₁ and Z₂ represent ahalogen atom, alkylsulfonyloxy group or arylsulfonyloxy group.
 12. Amethod for producing a polymeric light emitting substance of claim 4,comprising reacting a monomer of Y₃—Ar₁—Y₄ with a monomer of Z₃-A-Z₄ inthe presence of a Pd catalyst, wherein Y₃ and Y₄ each independentlyrepresent a boric acid group or borate group; and Z₃ and Z₄ eachindependently represent a halogen atom, alkylsulfonyloxy group orarylsulfonyloxy group.
 13. A polymer light emitting device comprising atleast a light emitting layer between a pair of electrodes composed of ananode and a cathode at least one of which is transparent orsemi-transparent wherein the light emitting layer comprises a polymericlight emitting substance according to claim
 4. 14. A flat light sourcecomprising a polymer light emitting device according to claim
 13. 15. Asegment display comprising a polymer light emitting device according toclaim
 13. 16. A dot matrix display comprising a polymer light emittingdevice according to claim
 13. 17. A liquid crystal display comprising apolymer light emitting device according to claim 13 as a back-light. 18.The polymeric light emitting substance according to claim 1, wherein Mis an iridium atom, platinum atom or gold atom.